I've read everything I can find on picking Family instances and I honestly don't see how I can do this...
I can't pick two Fighters in same "Fighters" Family, determine if the first Fighters has LOS to second Fighters, then if second Fighters.IsFoe (inst var) is True, set second Fighters to visible. I tried the two families trick, Fighters_1 and Fighters_2, this could work if you were allowed to have the same Fighter.Foe inst var on both families. But you cannot.
I think this may be impossible in C2