Boys will be boys................or will they?

There is a dynamic going on in my sons grade 1 class that is out of the ordinary. It is a dynamic that I am all too familiar with, as it occurred in my grade 1 year as well. I've never really heard of it occuring in a male circle of friends before, which frustrates me, because if I'm going to have only boys, I want "only boy" problems. Arghhhhhhhhh!
Apparently there is a group of about 5 boys who typically hang out together in my sons class. This group has 2 leaders, one of which is my son. (I think youngest children tend to be leaders of their peers, because they are already very accustomed to large groups of kids, and have observed how to manipulate people into doing what they want them to do. They may not get their way at home, being that they are the youngest, but amongst their peers they have no fear of telling others what to do.) The other leader of this group has parents that work full time, and aren't very strict about foul language, types of movies/shows their kids watch, what kind of video games their kids play, nor do they seem to enforce any kind of "fair play" rules in their household. Well, it seems that my son, along with this other boy, have created a type of "gang" that takes turns liking and not liking certain other individuals of the group. I find this horrific, because this is the exact same thing that I was a victim of in grade 1, and I am mortified to think that my own son is immitating a behaviour that I abhor. I THOUGHT THIS ONLY HAPPENED TO GIRLS!!!!!!!!!!!!!!!!!!!!!!!!!!!
I have been doing my best to instill values such as fair play, kindness, understanding, etc. in my son, and since I've discovered this situation at school, these values have been re-inforced on a daily basis. I only wish other parents would do the same. I've struggled with whether or not to notify the mom of the other "leader" child in this group as to what is going on, but it's such a hard call when you want to maintain a friendship with someone whose child is leading your child in the wrong direction. You don't want them to think that you're telling them how to parent. It's a tough call.
When your children are pre-school age and you encounter a situation like this, you can continue the adult friendship (like I stated in a previous post), and choose not to let the kids play together. But once the kids are in school, in the same class, there's not much you can do.
My prayer is that my son and this other boy are separated next year and that the rest of the boys involved move on to more healthy friendships.
Parenting is hard. Sometimes all we can do is give it to God!