Back when I had my first batch of chickens, I ended up with 7 roosters and 18 hens, one standard and the rest of the roos were various bantams breeds. At first I had everyone together, but then the poor hens were getting ganged up on ( one would pin a hen then all of them mounted her one after another, omg the poor hens), so I did end up making a separate pen for the roosters. I kept one rooster with the girls, and the rest of them had their own dude ranch on the other side of the yard.
In both settings the roosters were fine with each other, once they decided who was 1st, 2nd 3rd they very rarely challenged each other. They even seem to travel together in certain groups, and seemed to like being together, hanging out, eating, and rolling in sand together. Only three of them would crow a lot, the other four were fairly silent, but the three that did crow..ya..alot

one after the other. The breeds I had were standard EE, bantam EE, d'uccle, cochin bantam, and polish, so not very aggressive types, tho the EE bantams were the most feisty out of the group.