It is a learning curve, that's not a bad approach. I'm still not sure how many total chickens you have, their ages, and the sex, other than at least two are male. Free ranging in 8 acres that sounds like fairly typical behavior. The dominant male runs the less dominant out of his flock. The less dominant eventually might try to carve out his own territory and attract females or he may eventually go back and challenge the other rooster for his flock.
You don't need to answer these for me but maybe think about it. Why do you want chickens, other than eggs? How does having roosters fit in those goals? The only reason you need a rooster is for fertile eggs, everything else is personal preference. Personal preference can be pretty strong. Some people would not consider having a flock without a rooster, others don't want a rooster anywhere near their hens. Instead of looking at magic ratios of hens to roosters that don't work anyway, my suggestion is to keep as few roosters as you can and still meet your goals. That is not because you are guaranteed problems with more roosters, just that problems are more likely. Keep it as simple as you can. But with 8 acres you have options. It's not like you are trying to shoehorn a bunch of chickens into a tiny space.
It sounds like you already have some new chicks, sex and age unknown. It may be risky locking that rooster in with them now, especially if he is still a cockerel. I do not trust cockerels as much as I do mature roosters. Even a mature rooster would pose some risks. I think your basic plan is pretty solid provided they fit your goals. The question is when to lock that male and the new chicks in the new coop together for a few days so they become a flock and get used to sleeping in that coop together. A lot of that depends on their ages and how much room they have when locked in the coop or coop and run.
As Aart said though, what if you have another male?
