Pruners, he's awfully young to be able to sustain and make friendships as we understand them.
Ds at this age = no "real" friends at all apart from a rather hilarious folie a deux thing with the other really talkative child at nursery...
Ds at six = still bleating with genuine pathos about how one particular (impossibly wholesome and nice and therefore very annoying) boy at school had everyone after him to be his friend...and that no-one loved him bla bla
Ds at eight = popular boy in class, liked by all, with two good friends and a wider circle of four more he likes and plays with all the time. One of the good friends is someone he talks to about feelings and things - it's a very deep and mutually caring relationship. "Blood brothers", horse-trading as to whether they can persuade friend's younger brother to marry dd so they can be "real" brothers...
You really would not have given this outcome ANY credence at all when he was rising four. And, any children seemingly having a great and real social life at that age...their mothers are lying. It's a developmental thing.