My passion is gamefowl. In my little hobby I raise many young roosters that don`t especially like each other. To keep peace, I put them all, even various young ages, together in one large pen, under the guidence of one mature cock. The idea is, if anyone is gonna whip butt, it`s gonna be the old cock. I can keep them together peacefully in this maner until they are around 10 months old. Various mature cocks have proven to me that it`s not the cocks that will harm the youngsters, it`s the hens. They pose far more danger to new youngsters being introduced than a cock. I suppose there are exceptions and I would certainly observe for a while when introducing, but the answers to your questions are no and no.........Pop