I've noticed that also. Cockerels tend to not fight nearly as much in closed spaces as they do in more open spaces. I don't know why. Good observation. Welcome to the forum, by the way.
As others have said the two pullets will do fine on their own. I prefer a minimum or three though. They are social animals and really like company. If you just have two something can happen to one and you have a lonely chicken.
Right now your cockerels are going through puberty. They have been setting up the pecking order/dominance positions in the flock for a while but they are maturing at different rates. As the less dominant matures he has hormonal urges that tell him to take over so he may instigate fights. Sometimes those are not much but sometimes they can become serious. From what you are saying it doesn't sound too bad but it is hard to predict the future.
The boys will notice the girls, that's part of the hormones too. At that age it's more about dominance than sex. The one on bottom is accepting the dominance of the one on top, either willingly or by force. At that age it is usually by force. Sometimes it is not too bad, sometimes it can be hard for the faint of heart to watch.
Because of the social structure in a flock it is hard to determine which cockerel to keep because of behaviors. The dominant one is the flock leader and has certain duties, responsibilities, and privileges. For some of those duties he has to be dominant. How can he break up fights between hens if they turn around and beat the crap out of him for example? When you have two or more males the dominant one suppresses the behaviors of the other males. You don't know how the non-dominant one will behave once that controlling one is gone and he is left in charge. On the other hand the competition from the underlings can sometimes make the dominant one more aggressive or assertive than he would naturally be. Once the pullets and cockerels mature the flock usually becomes really peaceful but with them all going through puberty and especially the boys' hormones being so strong a pullet/cockerel flock can be really messy.
I tend to choose the more dominant male on the theory that he has more self-confidence so he can win over the hens more with personality instead of having to rely on force, especially once they all mature. You can never tell when a male will become human aggressive, which I don't tolerate. I think the more dominant are less nervous about their position so may be a bit better about this but I don't know. With yours I don't know which will be the more dominant in a couple of weeks as they go through puberty.
Now my standard disclaimer. The only reason you need a male is it you want fertile eggs. Everything else is personal preference. There is nothing wrong with personal preferences, they can be a really strong motivator. I typically suggest you keep as few males as you can and still meet your goals, whatever those are. That's not because you are guaranteed problems with more males, but that the more males you have the more likely you are to have issues. I don't know your goals so I don't know if 0, 1 or 2 is the right answer for you but I'd discourage trying two from what little I know.
Good luck!