Sniping in urban terrain is very difficult. One well placed mortar, RPG or gernade anywhere close to your hide can bring the overhead down on you considering every structure is concrete over there a ceiling falling down can take out a team. Direction of a sniper shot in urban terrain is determined very easily by the of a straw, pipe cleaner etc. placed into the entrance wound of the sniper victim and follow the angle of trajectory to the highest vantage point and 9 times out of ten thats where the sniper is. Then throw every thing at the position, no matter how well the sniper was hidden you cannot hide from shrapnel or mortars. Sad story
. And about the AAV it is designed to hit a beach head running dump off the grunts and go back to the LCAC, LSD or landing craft not to be engaged long range urban assault OPS. The Corps needs some Strykers for that.