Greetings
CleverCluck,
The pecking of your rooster's crest feathers, probably started as curiosity. But because of his immaturity, he did not know how to react, or was overwhelmed by the girls. Some roosters are slow to mature, or just have a very gentle demeanor.
I have a little ameruacana rooster that was very immature, and wanted to snuggle under mama's feathers at roost time. He got pecked, mercilessly for his efforts. He was a late bloomer rooster, as well. Each morning, I remove him from the pen. He has his own feeder and water outside the pen, in the shade. He is free to roam and explore, but is discovering that he is a rooster. So, he guards the hens for half of the day. When the hens are released to forage, the little rooster (Covey), is put into another pen. He is not allowed with the hens at this time. He needs to mature and develop certain rooster behaviors, first. At night, he sleeps in a crate in the main coop with the hens. I test his progress once a month, by allowing him to be with hens and observing behaviors. It has been slow going, but, I expect him to be with the hens full time, by August, or sooner.
Your young rooster needs to mature, and more importantly, he needs to heal completely from the injury. The hens could possibly kill him. It will be a different story, once he is 8 or 9 months. He should come into his full roosterness by then!
Hopefully you can arrange to give him time away from the hens, but still have the ability to see them.
Crested birds are sometimes irresistible targets for pecking. One of my crested cream legbars had a lot of her crest feathers removed by flock members. You will have to be vigilant of your other polish hen. She may be targeted, too, now that the rooster is out of the mix.
These are my thoughts on your chicken's issue. I hope I have been helpful.
God Bless
