Since it seems like most our complaints on this site center around our current point guards' defensive shortcomings, I'm thinking we would be more concerned about Asuma's defensive ability and potential as opposed to what his HS scoring/assist averages are.
Since I don't think the AAU/shoe summer leagues concentrate much on defense, I'm not sure film would show much in regards to his ability to learn rotations, angles, help defense rules, all of which are just as important at the college level as the basic "staying in front of your guy" talent is. The former can be taught, though it helps to have those instincts. But have we seen anything indicating that he is able or inclined to hang with quick, talented guards out near the perimeter?