Oh boy, you’re gonna get a lot of different answers on this one! The easiest answer is “1 roo per flock”, but personally I’ve never found that acceptable for mine. It honestly depends on the cockerels, and the head rooster. They are all individuals with their own personalities (which of course is why we love them so much!) . It’s not just hormones, they make choices.
In my case, my head rooster already lives with another adult roo, who is fat, lazy, and shows little interest (but not NO interest) in breeding (there are 11 hens). #1 Roo chases #2 Roo around the yard several times a day to prove his dominance, and if #2 tries to breed a hen, #1 races over and knocks him off. They almost never truly fight, though both are capable of injuring each other. My beloved and recently deceased Jersey Giant used to be #1, and he managed the other 2 roos quite well. I’m currently introducing my March babies to the flock, 5 out of 8 were cockerels. So far #1 Roo has accepted 3 of them graciously, and I haven’t tried the other 2 yet.
The March babies are about 10 weeks old now, and they have been in a separate pen with my bantams adjoining the main pen for a month. The bantam Cochin roo is on my

list because he can’t live with other roosters (he soundly and viciously beat up both #1 and #2 on his only visit), and he will guard bantams and babies untilI have a better one to do the job. Then he’s soup. That’s really the key to keeping roosters, I think, learn which ones to keep and encourage to be a family, and which to enjoy for dinner. I have 17 chicks in the brooder now and an incubator on its way from Amazon, and I will raise and integrate these just like the March babies. It seems to work. Besides, I’ve heard roosters are delicious.
With your situation, the biggest questions are, will they get along, and are you willing to feed them? If you are committed to their care, I’d say raise them with the girls and try to integrate them with your existing flock at the appropriate age. If your adults, won’t tolerate them, keep them separately penned as a bachelor flock. PLEASE don’t release them to freerange, as this attracts predators to your flock, since they will likely stay close. Bachelor flocks are awesome when you have the space. The boys get along great when they don’t need to compete over sex.