I have two with 11 hens. No fights. It's obvious which is #1, he chases #2 several times a day, but only 10' or 15' or so. There isn't even any contact much less pecking or real fighting. #2 has his spot on the roost away from #1, and he has to wait til everyone else is settled down. The only hen that looks beat up at all is my little BO hussy who runs up to one or the other of them, squats and ASKS to be mated frequently.
It just depends on the personality and/or hormone level of the individual roos. I've had other well behaved roos. The ones who are people aggressive or rough on hens don't stay here long.