I have all boys. I found that they needed to fight among themselves and their friends from time to time. They would fight, then a half hour later they were playing again.
They learn that there is always somebody else bigger and stronger who can whoop them, negotiating skills, and the ability to drop a grudge when the fight is over.
I also think it is better for them to learn this young while the damage they can do to each other is limited to a bruise or a bloody nose.
Sounds archaic, but it works.
Yep, I have two brothers and we fought all the time growing up. An hour or so later none of us knew what we were fighting about.
Maybe it is archaic, but the reality is that this is the way boys have ALWAYS been. We come “pre-programmed” this way, to try to change this is just plain stupid.