Would best be used in urban combat situations possibly & for stealth missions when going around a wall/making a lot of noise are not suitable.
Ozzisoulja: Soldiers are trained on obstacle courses. There is whats called a 12ft wall funnily enough it measures 12ft lol the technique to scale this requires 3 soldiers 2 boost 1 up he stays on top to assist with the second who also stays on top the 2 on top reach down and grab the arms of the 3rd as he jumps up the wall and is then pulled high enough until he can scale the rest himself. this implemented and a 2 man boost as stated by the OP would be a much needed feature for the game. yeah it may be a long winded animation or it could be done in three segments (probably better and any segment cancelled at any time in case of contact) but this could allow for better fire/overwatch positions not at this time available e.g on top of a container and would be great to make people who work together as a team usually get an added benefit from doing so. But also any soldier should be able to scale a 6ft wall at least.