I've been repeating this since the end of the season...
The ability to draw fouls is an underrated attribute for the best players of the NBA (and he did so at an elite level in College). The league leaders in Free Throw Attempts are a who's who of the best scorers in the league. Instead of avoiding contact ala Jeff Green (part of the reason Jeff has plateaued), he looks for it. It's a skill that is crucial for closing out games in the NBA.
Smart's ability to guard multiple positions at a high level combined with his physical attributes and ability are going to make him a mismatch against the vast majority of his opponents. Too strong for 1's, too quick for 2's, and he can shutdown either.
His shot? Smart won't be the first nor the last to come into the NBA without a refined shot. Even the best shooting prospects need time to develop their shot at the NBA level (McLemore last year and Beal before him). Matter of fact, most of the top players have had shot issues coming into the league.
Whatever the case, whether he pans out or not, Marcus is going to prove his ability as a CELTIC.