The type of vehicle matters a lot in my opinion. As usual I hope that someone we all know about hops in the thread and clarifies this, but I belive the type of vehicle changes what a platoon of mechanized infantry can and cannot do. The BMP-1 or 2 has a given amount of internal space, a given position of soldiers carried inside, a specific weaponry. Different assets mean different conditions of the fight. You can learn how to fire a generic rifle, but training with one, specific rifle is another thing.