Smart was a SG before his time at Oklahoma State. The Analytics folks compare him to players like Tyreke Evans and Harden. It seems more and more that Rondo is staying if for no other reason than there is no market for him, either traded or as a FA. So with that being said, is it possible that Smart who can easily guard SG's be moved back to that position? So many teams are moving that way: OKC, Phoenix, Toronto and others. Perhaps that was the plan all along?
The fact that Smart played mostly SG in high school isn't really all that relevant.
Most NBA players were bigger than their peers in high school and so played 'bigger' positions there than where they are suitable for in the NBA.
I.E. - there have been and continue to be a ton of former high-school centers who are playing PF & SF in the NBA.
What matters now is how his particular physical makeup and skills project in the NBA.
I see him as much more effective with the ball in his hands than off-the-ball and physically, he should eventually prove a nightmare for pretty much all NBA PGs to handle on either end of the court.
Against NBA-caliber SGs, while he still has some physical advantages over some, not so much over many.