Roosters are where romance meets reality as AArt says. It is a good truth. Roosters are a crapshoot, and often times people vastly underestimate the violence a rooster is capable of producing towards people and or towards each other.
If you have multiple roosters, you need a plan B (which is what I think you are trying to do) set up and ready to go. A hook or a fishnet so that you can separate fighting roosters.
Once they leave you, you have no say what others do, it is really none of your business. Selling a rooster is possible, if you have some very nice birds, but it is not likely. Roosters are a dime a dozen, so to speak, as more people have roosters that are ruining the whole chicken experience, than people that want roosters. Rehoming for most is a lovely idea, but not a practical one, in as they can't find a home for them.
Separate coops will help you keep them. The thing is you really cannot change natural chicken behavior, and a lot of the behavior is pretty ugly if you are in a smaller confinement area. Separating them is really your only option and it is an expensive one.
You will be able to tell, when your pullets and hens become bare backed, keep hiding in the coop, are repeatedly harassed for sexual favors and upset by fighting birds.
People often come to this forum with some preconceived ideas about how this will go, but chickens are chickens, and do not always act nice and get along. Wishing will not make it so. Sometimes a bachelor pen will work, some roosters it won't work.
Mrs K