Over Grooming.... I think?

I am pretty sure my little boy, June is over grooming. But I’m looking for a second opinion. none of the patches where he is missing for look red or irritated, they also do not have any scabs, Along with clean margins. He is currently active and doesn’t appear to be excessively itching. It’s been about two weeks since I noticed these spots on his back end and they have not really changed.