Integrating Buff Orpington cockerel into flock with hens, pullets, and other cockerels

[SunriseHills]

Hello! Hope ya'll are having a good day. Recently, we picked up a 4 mo old Buff Orpington cockerel from one of our neighbors. He has been in quarantine for three weeks inside of a large dog crate (two weeks where the crate was away from the flock and one week with the crate being in with the rest of the flock) and hasn't showed any signs of illness. Since he appears to be healthy, we would like to let him out with the rest of the flock. Our flock consists of 15, 1-3 yr old hens, 18, 3 mo old pullets, and 5, 3 mo old cockerels. I would like to add that two of the cockerels are Black Copper Marans, two are Black Ameraucanas, and the other one is a Splash Ameraucana. I would also like to add that we are re-homing one of the cockerels and one of the pullets together tomorrow, and plan on rehoming two more cockerels, in a couple of months. Also, the five cockerels grew up together, and rarely get into any squabbles with eachother. So, to make a long story short, I attempted to let the Buff Orpington cockerel out with the rest of the flock this morning, but he wouldn't come out of his crate, and as I waited there with the door open for him to come out, two of the cockerels (neither showing any aggression whatsoever) went into his crate (most likely because they noticed some of his spilled pellets), and he immediately grabbed one of the cockerels by his comb and wouldn't let go of him until I forced him to. Thankfully, the cockerel's comb wasn't injured. I plan on making a calming tea for the Buff Orpington cockerel later (yes, I make teas for our chickens, lol), and getting him out of his crate into our flocks' large area (because we're thinking that his sudden attack was caused by him feeling trapped in his crate with two unfamiliar cockerels entering his 'territory'), but would still like to hear other's ideas and opinions. Thank you!