Despite Kanbei's overwhelming number of cities (and the fact that he's Kanbei, superior in offense and defense), this map is very easy if you select the right CO.
You may notice that there are a total of six COM towers, most of which are readily accessible for the player to quickly capture. This is the perfect situation for Javier to come into play.
If you doing this without skills enabled, fear not, capturing all six towers when playing as Javier gives him a tremendous boost in defense and offense, despite not having any bonus skills. If you are playing this with skills enabled, use a skillset that increases your movement, or further enhances your offensive abilities. Depending on your CO level, a good setup might be:
- Pathfinder (forest movement = 1)
- Brawler (direct attack +8%)
- Sniper (indirect attack +8%)
- Tower Power (COM tower +5% effect)
The reasons for the above are fairly self-explanatory: boost to offensive, neutralizing the forest terrain (for fast rushing at the central forest region), and further increasing Javier's tower abilities.
First, focus on capturing the four central COM towers. You should be able to do this within a few turns if you keep building infantry at the center two factories. Meanwhile, save up some funds so that you can build an APC and infantry at the leftmost factories on consecutive turns (this should be doable as long as you only build infantry the first 2–3 turns). These two APCs and infantry will rush the top and bottom COM towers along the road, in addition to sneaking all the way back to slowly capture Kanbei's massive megalopolis.
Once you have secured the four central COM towers (and are working toward the two others), station infantry on the two cities at the middle of the map. With four COM towers, Javier's infantry should withstand Kanbei's neotanks quite easily. Set up a defensive position along the two bottlenecks, and build a couple artillery to support your "tanking infantry". You'll probably spend quite a few turns here just holding back Kanbei's rush of neotanks. Once you have all six COM towers in your possession, your infantry should be taking 0–1 damage as long as they have decent terrain cover (three stars or more). Even Kanbei's neotanks will have trouble cleaning up your measly infantry while only taking 1 damage.
By now, you can start focusing on the offense. Save some funds for 1–2 turns, and start alternating some tanks/midtanks. These funds will become more readily accessible once your two APC and infantry teams start capturing the rightmost cities (avoid any stationed rockets if Kanbei happens to build them).
Once you have built up a small enough army, rush the two bottlenecks (really easy if you have Pathfinder). Javier's tanks should be able to attack Kanbei's neotanks without taking considerable damage. Target Kanbei's infantry/artillery/rockets first, and set up your own artillery to support them. No matter how you approach this however, rest be assured, your six COM towers will definitely provide you with superior defense.
With funds slowly increasing, you should be able to start building a fair amount of midtanks/neotanks every turn. By now, Kanbei is probably forced along his own factories. Save up your SCOP then take him out in one blow.
Estimated time of completion probably will be around 20–24 turns with skills, and around 22–26 without skills. This does depend on how long you want to hold your defensive position however. An S-rank should be easily achieved if you follow the above.