Rooster pecking other roosters

So we have 3 25 week old brahma cockerels. One cockerel seems to be the leader and clearly acts like it. He pulls out the neck feathers of the other two cockerels. At first we didn't know if it was just molt or if another one pulls out their feathers. Can i get any tips on what i can do? Nugget here gets picked on the most.
And he even pecks his own little brother pollo too.

You can't really see it with him, but it's still there

tinyurlis.gdv.gdv.htu.nuclck.ruulvis.netshrtco.de