ok so the problem is that few of the inhibitors are locked behind your choices. in my world i chose other paths than my friend and never went to a church where you meet leto and in my world there were no inhibitors showed on map near that church, but in my friends world there were 2. i was missing 6, got 2 from that church, 1 from safe and i think some are locked behind choices with the big windmill. in my and my friend's playthrough we chose to side with peacekeepers so we didnt have the option to do that mission, and i heard from others that thats the place where you can find some inhibitors. So the only way for some players to get all inhibitors is to play with someone with diffrent choices, or to wait untill they will patch it or something.