As for high school, one could point out that last year his team was one of the best in the state. They lost their top player to graduation and now it's Martin's team. They are a ~.500 type team this year despite his individual production rising. That doesn't necessarily mean much about Martin specifically, but it's important to consider along with other factors.
With regard to his ability and future impact... I see his value as a guy who could mix it up inside, rebound, defend.. not sold on his ability to shoot the ball away from the basket (or at the FT line
). I think he'll compete, has an edge that can be good for a locker room if used the right way.
Probably will struggle with fouls early on; may be a slow start... but he does have the ability to be a solid player. And a player of his type is needed on the roster.. so not a bad fit at Minnesota.