I said nothing about gaining something out of it, repairing condition and getting additional ammo is a piece of cake. Btw, There is nothing stopping you to just shoot each other in your platoon base, usually like 400 overall rep lost. And even if you lose more, like 4k.. Can it even be considered as a loss?
A shooting range with a practice dummy (whose settings you can change, like dr/dt) I'm up for, but arenas.. Whole phoenix is an arena :/.