We ran into a similar issue at preschool. "Socialization" sounds nice in theory. In practice DS ended up with little Mr. Poor Impulse Control smashing him over the head with a toy (although I am just a layperson this kind of interaction would seem to have little developmental utility).

A mixed age group might be helpful - our guy is much happier playing with kids 2 years older maybe b/c he can actually talk to them. I have no idea where he we end up intellectually - right now I just want him to have fun and play and not be miserable.