It's settled, then. Instead of a single tank, four players will be controlling a tank each (three crew in one), forming a platoon lead by a Lieutenant (me). There'll be a language barrier that will remain until solved by a wizard or something else. The rest will be the same as what I had planned. Unless anyone has any more objections, then the OOC will be up later on. 

On a side note, the players on the fantasy side can be anything they want so long as they're not too blatantly overpowered.