I have had chickens my whole life. Many times, with two roos. I have only had success when it is two roos raised together. They all lived their entire lives with established order. But I have never been successful at introducing a younger roo to an established roo. It has always ended up in blood shed. I am sure that with the right birds, and experienced owner, it can be done. But I doubt it can be done very often. I would say it's the exception to the rule. When they grow up together, seems they learn early who is the bigger, stronger, more dominate one. And the other just submits. But when you introduce a new rooster, to an established flock, well. The leader can, and most likely will, be challenged. And once a real challenge has been done, trust can't be established. Just my two cents.lol sorry that you had to deal with this. And sorry your rooster lost an eye. He is really vulnerable now. I say he would be just fine with his girls. But first chance the new rooster gets, he will most likely attack again. Especially since it sounds like he won the challenge.