You could just try to get close enough and the shout and ask if they are enemy!:rotfl::rotfl:
Seriously though one of the joys of GWX is that you can flex on how you want to play. If you want to use the external camera to work out who's who then you can. If not then you play the way it was designed and try to get into a position where you can ID them properly with the UZO or binocs. You can almost rest assured anything near Britain with an escort it fair game. Almost
Gute Jagd!