My question is do I keep all the roosters? Will they fight if I only keep 2 roosters? (I have someone who wants one of them), or do I keep them all to keep the peace?
My general suggestion is to keep as few males as you can and still meet your goals. That's not because you are guaranteed more problems with more boys but that problem are more likely. It sounds like with your goals that means two boys minimum, one Chocolate and one Lavender.
Now the trick is to determine how to keep them all. I try to go by what I see happening instead of what people (or even my experience) tells me might possibly happen. My experience tells me that many different outcomes are possible so I need to be ready for about anything.
Some people manage to keep two or more roosters with the flock without much drama. Sometimes that just does not work. One type of drama is that they determine which one is boss, which is dominant flock master. In a flock like yours with older hens and cockerels that's likely the dominant hen right now. As the boys mature that will change. It could involve a fight to the death between the boys or maybe with that dominant hen. Or they could settle that with basically no drama for you to see. Each situation is unique because each chicken has its own personality and we house and manage them differently.
One kind of drama, especially with immature cockerels, is that they probably will want to mate with the girls, either the pullets their age or the older hens. Eventually both. When they go through puberty the hormones take over, they have little if any self-control. It can get pretty violent but sometimes it's not really that bad. But usually it can be hard to watch. As someone on here once said watching them go through puberty is not for the faint of heart. Immature cockerels and pullets usually don't act like mature roosters and hens.
This excess desire to mate can stress the girls. They might avoid the boys by staying in the coop or even up on the roosts in the coop. They may have trouble eating and drinking enough from avoiding the boys. Since mating can sometimes be violent injury or even death is a possibility. Or the girls may lose enough feathers that they can be injured. Usually that's on their backs where the boys feet stand or the back of the head where the boys grab hole during mating. That head grab is part of mating, it's the signal for the girls to raise the tail out of the way so the boys can hit the target. It's instinctive for both boys and girls but if it is violent feathers can be pulled, which leaves that bare skin open for injury. In my flock this stuff usually does not happen, but it can. Usually the more room you have the less likely you are to have serious issues but they can possibly happen even with unlimited room. None of this is certain.
Once the immature boys and girls become mature roosters and hens things tend to settle down a lot. They don't always but they tend to. The trick is often getting to that point.
You said you want to breed different hens and roosters. That lines up pretty well with being ready for anything. After a mating the hen stores the sperm in a special "container" near where the eg starts its journey through the hen's internal egg making factory so that egg can be fertilized. That sperm can remain viable for over three weeks. That means you need to separate the hens from any rooster you do not want to be the father for over three weeks. That means separate breeding pens. If you build those breeding opens now (including coops) then you can separate them when you need to, if you need to.
You'll read a lot on here about hen to rooster ratios. I don't believe in those, I believe in going by what I see. You can have the same issues with 1 to 30 as you can with 1 to 3. You may have no issues whatsoever. Breeders often keep breeding pairs or trios with no problems. That may be one rooster with one or two hens. But there is an open secret that often makes it work. Those breeding pairs or trios are mature chickens, not immature cockerels or pullets. You can still have issues but with adults it is much less likely. With immature chickens the odds of problems go way up.
In your situation I'd get rid of that third boy. You don't need him and he is not going to help. I'd build those breeding pens so they are ready if you need them. During breeding season and if you have to separate them for other reasons that means they don't all free range together or share all of that run so be generous with room when you build them. Then see what happens and base your actions on what yo see.
Good luck!
