For ambush, a very effective tactic would be to have a sniper wait and watch from the balcony, the VIP will normally have to run across the door from the other side of the alley. Another approach would be to rush all the buildings surrounding the immediate area of the extraction point pinning down the enemy before they can reinforce it. My tip for ambush would be to spread out as much as possible and cover as much ground as you can because the Escort team can pop out of any alley at any moment. The VIP likes to hide in Dusk, it is always a good idea to search every corner as you move but always make sure that your flanks are covered or clear.
The best probable strategy is to run for the VIP first and make sure he gets back with you alive, then run for the arches by the main road. if you can secure that area and suppress Ambush long enough to sneak in a couple troops behind the building, you are sure to get the VIP out. Always make sure to leave at least two units to protect the VIP while you flush the ambush team out from hiding.
A tip for escort is to never let the VIP out of your sight. There are a lot of places to hide on this map and anyone of them, especially the road next to the extraction point, is easily rushed and defended by assaulters.
Another tip for escort would be never move around with the entire team with the VIP in the middle of your group, one flash-bang can make all of you blind and deaf. It is a better choice to send fireteams forward first, split up and secure intersections as you move rather than running through the entire road in one go. Remember to keep each other in each other's sight, do not loose track of each other otherwise Ambush team can pick you off one by one.
Always make sure that you have someone make sure that every single pathway and alley around the extraction point is clear before moving it. This area is most likely to be rushed by both sides. If you can secure these areas first, you already have the winning advantage, but that is if you maintain communication and teamwork with your team.
This is quite a simple design for a map. There are only a few major roads, but there are a lot of windows, doors, and other places to hide in. Always make sure to check every one of them before moving in, especially for escort team and the VIP.
In this map, taking things slowly isn't as important. With narrow alleys and corridors, normal walking speed is preferable, unless you would prefer to use stealth to your advantage. The main idea on the other hand is to gain control of as many vantage points around the extraction point as fast as possible. Having control of the immediate area around the extraction point can mean certain victory, unless your team makes a mistake by moving out of the area and letting the other team in.
It is also recommended that your team make as much use of concentrating your firepower on your enemy. Always have your support gunners or AR in front and down low to allow riflemen directly behind them to shoot without obstruction or risk of ROE violation. To do this you must move in pairs or in fireteams which ever is possible. Do not move too close to each other and do not stand directly behind a team-mate while you are on the move, an ambush that surprises you and make you open fire has higher chances of hitting your team-mate as well. Move around by shuffling, or walking and strafing left and right minimizing chances of ROE violation and maximizing your fireteam's firing angle. When in proper position, a fireteam can overpower an entire enemy squad without exposing any flanks or risking any team kills.