It would make it easier to get a grouped soldier teammate to mount the desired vehicle if you could simply point at it on the map and order him to mount (assuming that the player is on the other side of the map). This would be especially useful for when you want your men to board the same vehicle when there are many vehicles in a small area. Or if you want them to board separate vehicles and have to select the soldiers individually. I hate it when I am trying to get them to board different vehicles and I accidentally order one of them into an already occupied vehicle. Especially when all of the vehicles are the same kind.