I should have clarified my one point-- the thing that has made this work for DD is peer tutoring math(s).

So I didn't mean tutoring FOR your mathy kid-- by BY him.

This also can go a long way to improving social skills and confidence with older peers, too, which is ultimately a very good thing. DD has always had pretty darned good social skills, but they have definitely improved with tutoring. And she's found something that really lights her fire-- teaching. smile
Schrödinger's cat walks into a bar. And doesn't.