I just want to say having 15 males that while they do tend to get more territorial I have only had two that we had to keep away from others and it wasn't even permanently. What I have done is make a coroplast cage and split it with grids, then they have time to get acquainted- after quarantine of course.
Males do need their space, and I agree getting a third one in there sometimes makes it easier for the newbie.
Males do need their space, and I agree getting a third one in there sometimes makes it easier for the newbie.