Rating: Moderate (low resources)
At first glance, this looks like a scenario where you have to cheat in order to survive. Let's do a detailed analysis of the starting position.
You can see from the Achievements menu that the Izumo have about 50 units and no villagers. This means that they are static and can be ignored for the time being. Brown and Yellow combined outnumber you by about 6 to 1. A more appropriate comparison is that they outnumber you 3-1 in villagers and 2-1 in bases, and they have about 10 combat units, while you have none, and no chance of getting any for some time. So they are exponentially ahead of you, and will remain so for quite some time. At the same time, you are going to have to attack them and occupy their positions early. It sounds impossible. It's not quite impossible, but very careful analysis is required in order to succeed here. This is definitely an expert scenario, but no cheating is required. There is an unlikely random event that might wipe you out early, but it's pointless to play with such things in mind. Just restart if it happens.
You certainly have no hope of accomplishing anything in the Stone Age (but see Note 2), so your immediate objective is to get into the Tool Age as soon as possible. The buildings that you will use to advance are a dock (this looks like a water map) and a Granary (so that you can research Wall), plus probably two Houses, so you will need to collect 20-80 wood. You will also need to collect 100 food. If you stick with your initial 3 villagers, you will need 12 collection trips. If you get one more villager, you will need 17 collection trips. Since you probably need to assign one villager just to build the required buildings, the time to start Tool Age research will be about 6 collection trips either way, so you should always get the fourth villager. If you get 2 - 5 more villagers, the required time will be 7 or 8 collection trips. For the next group of 4 villagers, the required time will be 8 or more collection trips. Exploration time is being ignored here, because you are not going to be doing much exploring until much later; your one Builder will do all the early exploring. The time to actually produce a villager is significant, and it has a big effect if many villagers are produced. Hunting micromanagement also takes up time. The measured times are actually 3.0 minutes to start Tool Age research with 3 villagers, and 4.5 minutes with 10 villagers. Read the end notes for more details.
You have 300 food immediately available via foraging, and about 360 from Gazelle (assuming you hunt each one with 4 villagers). This limits you to 11 new villagers, but really only 8, if you reserve some of that food for immediate Tool Age uses. There is also the consideration that you can probably only have 10 villagers efficiently collecting food here. There is an upper limit to how many villagers you can actually have, but that limitation does not apply this early. The big unknown is whether you need to allocate your early food to producing Clubmen. We are going to assume that this will not be necessary. We are going to produce 6 new villagers and then research Tool Age.
Resources are in very short supply here. You do not have any stone mines, and may never get any. You do not have any gold mines, and may never find many. In addition, you are critically short of food AND wood. Farming is out of the question, so all you can get is wild food, and that is extremely limited. In your initial area, you will find a total of 41x40=1640 wood. In addition to what has already been requisitioned, you will need a Barracks (125), an Archery range (150), a Storage Pit (120), 4 Scout Ships (540+30), a Transport (150), and a fishing boat (50), for a total of almost 1200. Everything else will need to be allocated for repairs. Even so, you also need to produce archers and get the first missile weapon range upgrade, and it is immediately obvious that you are in big trouble.
You will be unable to get any more wood to the east before defeating Yellow. That territory is heavily patrolled by enemy troops, and you don't have enough food to produce troops of your own. You will quickly find an island in the west map corner, and you will need to get onto that island right away. That is why you MUST have the Transport. If you are unable to afford the Storage Pit, then you could in principle distance harvest, but in practice, it means that you have lost the scenario. Also see Note 3.
Space in your initial territory is also extremely limited. Therefore you need to place each building very carefully, and there really are strongly optimum positions. There is a short cliff just past your Towers. Build your first two Houses right up against it, on the near side, in its east corner. This is on your Builder's route to the east, where he will build a Granary. It also leaves you space to build a 3x3 building right against the map edge. When your Builder has built the Houses, he can move a bit further east. Explore just enough to find the choke point. You will wall that off soon, but for now, build a Granary here, leaving enough space around it for some farms, but not interfering with the wall. Ignore the trees; they won't be there long. If you move too far east, you will trigger an immediate attack, and then you will have to restart the scenario. When the Granary is finished, send the Builder back west for other duties. Pick some other villager to move to the far west of your base and build a dock. Build it on the NW side of your base, leaving enough space to either side to not interfere with other potential buildings.
You will need to eat each Gazelle. If you delay, they will tend to run away, and that will actually be a significant problem. Therefore you need to hunt them as soon as you can muster 4 villagers. You will need to time this very carefully, because, in order to minimize spoilage, all 4 villagers need to start work at the same time, and you don't want villagers standing around doing nothing, and you don't want to pull villagers from one task to another when they are actually carrying something. Your best bet will be to use 3 villagers that have just deposited something at the Town Centre at about the same time, and a new one that just got produced near that time.
Some people may wonder why all these details are being discussed. The fact is, your initial situation is so critical that if you miss even a few of these details, you will probably lose the scenario.
There is a small and completely random chance that you will be attacked very early. If this happens, just restart the scenario. You have no reasonable way of dealing with such an attack.
If you have done everything correctly, you will start the Tool Age research at 4.0 minutes. You should now allocate all of your villagers to wood collection, except that 4 (or 5) finish off the Gazelle. Produce one fishing boat. Find a likely fishing spot, and then just wait to get into the Tool Age. It turns out that there is only one fishing spot. Oh well, 250 food for 50 wood is sort of like a farm.
Research Wall and wall off the nearest choke point completely. This requires 7 wall sections. If you've made it this far, save the game. You cannot afford to build any Towers, now or perhaps ever, because you will need to reserve all your remaining stone to repair your wall.
Produce 4 Scout Ships. Explore as much as you can with them as quickly as you can. You will need all of them in the east to fight off the hordes of Brown War Galleys that might already be arriving. Fortunately, they only show up one at a time. Mostly. Hopefully. Yamato Scout Ships are almost as good as standard War Galleys, but you will still need to micromanage the naval combat to avoid some damage. If you run out of wood for repairs before you have a new income stream, you have lost this scenario. If a Brown Transport should happen to show up, SINK IT on the way in at all costs. You may need to physically block it with your ships.
Build a Barracks and Archery Range. Tuck them into corners where they won't interfere with potential farming. Don't produce archers until you have to, but don't expect to be able to avoid it.
Produce a Transport and get a group of villagers over to the island in the west corner of the map. How should you deal with the Alligators? You are sufficiently short of food that you should want to eat them. Unload one villager on the very SE edge of the island and lure the two nearest alligators towards him. This will open up a space for landing. Land a bunch of villagers between the two pairs of alligators and run right into the middle of the island. Villagers can typically outrun Alligators, and Yamato villagers are fast. This island is secure. Build a Storage Pit and start sucking in wood. Ignore the gold and food for now. If necessary, farm for food in your main base. The most important thing now is to get something like 6 Scout Ships into action. As soon as you accomplish that, the scenario is effectively over.
Crushing your Enemies
You can now win any way you like. You will find out that your enemies are all actually quite weak. For example, 6 Scout Ships is all you need to defend against anything Brown might throw against you. 6 War Galleys is enough to crush Brown. Of course, you will still need to do lots of ship repairs. Three Bowmen and maybe a couple of Axemen are quite enough to finish off Yellow. However, some of this is hindsight.
The prudent and proper approach is to improve your economy, get into the Bronze Age, upgrade your Scout Ships as much as possible, and then explore to the east. You don't find any good way of attacking Yellow with your fleet, so you will have to go after them with ground troops. Produce one Scout and one Cavalry, and ship them, plus three archers, into Yellow territory. It is neither necessary nor appropriate to break your wall at this time. Yellow remains in the Stone Age and pretty much will just roll over and die when your troops arrive. They won't even be able to get any hits on your troops. You will now be able to claim a lot more space and wood, neither of which you actually need, and probably 800 gold. Yellow never had any particular use for gold, and never had more than a handful of villagers, so they have left most of their gold for you.
With Yellow out of the way, you can turn your full attention to Brown. Ship some villagers over to Yellow territory so that your ships can get repaired close to the action. Then just do a standard naval assault. Brown has many archers and some Towers, and will keep producing War Galleys one at a time. Your ships outrange the Towers, the archers are much smaller than your ships, and you will outnumber the Brown ships as well as outclass them. Therefore resistance is futile. You will need to attack the Brown dock in order to kill the repairmen, but do not destroy it! Eventually, Brown runs out of villagers, although they still will have some troops and Towers left inland.
At this point, you need to decide what to do with your gold. You have 940 gold for sure, and maybe 800 more from Yellow, and Brown may have left you some as well. If you are at the low end of the scale, then you should probably stay in the Bronze Age and just get a bunch of units. 4 priests, 3 more Cavalry, 2 catapults, and 5 Composite Bowmen will cost you 940 gold, and that is quite enough to finish off your enemies. You can supplement your Bronze Age units with large numbers of Tool Age units. You can also recruit Izumo units. The Izumo have Iron Age technology, but no upgrades at all, and that means that their entire army is effectively of worse quality than most Bronze Age troops. For example, basic catapults and +2 Composite Bowmen outrange their Towers. You won't face priests until the very end, and at that point you could simply rush them, although you have better options.
If you have significantly more gold than the minimum, collect exactly enough to research Iron Age and Coinage, and bring in the rest afterwards. There are a lot of very useful Iron Age upgrades that don't cost gold or stone. For example, your warships would be able to eliminate a lot of the Izumo Towers with impunity, and your catapults would be able to eliminate the Izumo priests safely using indirect fire.
Bear in mind that you really have an infinite amount of gold in this scenario. You can trade for gold at the Brown dock at about 1-1. Trading for food with maximum farm upgrades (475 food for 75 wood) means that every two trees are equivalent to more than one full gold mine. That's far more gold than you can ever use, although it will take a long time to collect it. Since the Izumo are static, you could simply set up the trade route and walk away for an hour. In this situation, there would be no reason at all to not use the gold cheat. However, as has already been stated, the Izumo are actually quite weak. You can win any way you like. You don't need a lot of upgrades, and you don't need a lot of units that cost gold.
All you need to finish off Brown is one basic catapult in addition to what you already have. There is a good chance that you will still find a couple of gold mines in Brown territory. You are unlikely to find any stone. The lack of stone doesn't matter anymore. The only time you might want stone in this scenario is before you get onto the corner island, because it would have been useful to build a couple of Towers to defend your initial base.
To finish off the scenario, assuming you have enough gold, get a group of horse archers, a couple of catapults, a couple of priests, and a couple of Phalanxes. Upgrade these units as much as you can, and then lay waste to the Izumo. Resistance is futile.
1) One of your villagers needs to be allocated to building all the required buildings and doing any necessary exploration. It might as well be the same one that does all of this. If you produce no new villagers, then you need 12x10 new resources (100 food, 20 wood) to get into the Tool Age. This means that each of your two other villagers needs to make 6 collection trips. One collection trip takes about 30 s, so you will be ready to research Tool Age at 3.0 minutes.
If you produce one new villager, which takes about 20 s, you will need 17x10 new resources. Your villagers will collect 2, 3, 3, 3, 3, and 3 loads, so the time to research Tool Age is 6 collection trips.
If you produce two new villagers, you will need 25x10 new resources. Your villagers will collect 2, 3, 4, 4, 4, ... loads, so the time to research Tool Age is 7 collection trips. If you produce three new villagers, you will need 30x10 new resources. Your villagers will collect 2, 3, 5, 5, 5, ... loads, so the time to research Tool Age is 7 collection trips. If you produce four new villagers, you will need 35x10 new resources. Your villagers will collect 2, 3, 5, 6, 6, 6, ... loads, so the time to research Tool Age is 8 collection trips. If you produce five new villagers, you will need 40x10 new resources. Your villagers will collect 2, 3, 5, 6, 7, 7, 7, ... loads, so the time to research Tool Age is 8 collection trips. If you produce six new villagers, you will need 48x10 new resources. Your villagers will collect 2, 3, 5, 6, 8, 8, 8, ... loads, so the time to research Tool Age is 8 collection trips. If you produce seven new villagers, you will need 53x10 new resources. Your villagers will collect 2, 3, 5, 6, 8, 9, 9, 9, ... loads, so the time to research Tool Age is 9 collection trips.
The optimum number of villagers to get is not obvious. However, it is not good enough to just get into the Tool Age as soon as possible; you also need a high income stream.
Some other details are being ignored here because they don't have much effect.
2) It may be possible to defeat Yellow in the Stone Age. However, if it works, it still requires serious cheating, because you have to know the dispositions of your enemies and their future behaviour, without having any valid way of knowing these things.
3) It turns out that you can actually abandon your initial base and regrow on the island in the west corner of the map, although this must be considered a fall-back position in case things go badly, instead of an actual valid strategy.