Never had any problems with mine - I keep all mine together, how many can vary, usually between 2 and 10. They have butting matches, but no serious bouts. Best to keep them away from the ewes unless tupping, but two is better than one on his own and three apparently is better again as the third one helps keep the peace. There are a few posts on this - look back a few months, there's quite of bit of info by what I can remember. Cheers!!