The crested Pekin I'd be worried about since there isn't skull under the crest and if they start grabbing onto it can seriously injure him.
@thumper650 has dealt with only drake flock and maybe able to give advice on how to handle this, When I had 4 Muscovy drakes we built stalls inside our coop so the drakes wouldn't be beating each other up at night. They also had tops framed in wood with hard ware cloth. In the day time they had their own part of the fenced property to roam with their own females. I know this is a different scenario but at night when everyone is suppose to be sleeping the stalls worked out great to keep the peace.