Amazed this hasnt been locked yet....that being said....
1st, the GV damage model is significantly different then the aircraft one. "supposedly" there are kill zones. You can playaround off line now and experiment yourself. I can tell you that there are two spots you can kill a tiger in (with PZ) at 1200 and 3 at 800...not on 1st ping usually...but 2 almost all the time....of course you need to be able to hit them. Since AH doesnt have any published info on this those who know do have a significant advantage....
2nd, the randomization is pretty extreme at times...you can hit a guy 4 or 5 times and get nada and get popped on 1 hit....or you can be on the good side of the draw...
3rd, you can certainly "game the game" more in the GV mode then in the other aspects...thats not a hack...just exploitation of a flaw in the game.
4th, some of it is simply by choice...in AH the ack is deadly at 1200 but the 37mm in M-8 is useless.
All that being said there a handful of guys who defy statistical analysis. If this was a casino instead of a flight sim they'd get dragged out back then told to not come back once they got out of the hospital:D