I'm pretty sure that small Duke can change his size and gender. Cause I'm pretty sure each kingdom only has one Duke? Correct me if I'm wrong haha but remember the lady we saw? I'm think she and the little Duke are the same person.
He kind of is, I think? He has 3 forms--a young boy, and adult woman, and an adult man (which we haven't seen yet, but apparently will in S2 according to the author)
I wish the small duke goes with the glasses dude. (after growing that is) I'm more curious about how they're relationship would progress.