I dont see why people would want to disable it. its just part of the kind of game it is in my opinion. If we go like that, why not put an option in to turn off turn-based combat to

Just let mods add that option or at least make sure the option is normally automaticly on when someone starts the game.
If people start this like a new game and then immediatly get asked if they want to turn off friendly fire.. there is a chance they might pick yes and miss 50% of the game's fun :P