I have a couple bachelor pens... grouping birds by temperament seems to give good results. There's a high energy, small-rooster pen with a tree and some bushes in it (that's where the killer silkies live), and a "mellow" pen where some placid large roosters (Buckeyes) keep the peace among a...
Based on my own experience, problem roosters are more likely to be problems because of their inherent personality - their individual personality, as well as the typical personality of their breed, and any particular personality of whatever strain they are from. Handling, cuddling, asserting...