Most people's reasons behind it seem to be because Dom is harder to find again, but tbh whoever leaves isn't coming back. I don't like having the same villagers more then once if I've had them for a while.
I had Pietro as my mandatory camper. At first he creeped me out, but he grew on me, with his facial expressions. I think he fits the smug personality well. Months later he started to bother me again. I'd say him if you like clowns, as he has a unique design. But Dom is cuter in another way. Maybe if you're looking for a jock that's not really a jock?