Smart and Noel are very much the point guard / center versions of each other, being extremely gifted defensively and questionable on offense. Historically the center wins that comparison hands down, but we're in an era where the world champions were trotting out Draymond Green at center and a shutdown wing defender won MVP. With Smart you are also getting 3 years of control, instead of 2, and no major injury history. That matters.
That said, it's going to take much more to get the #3 pick included. Maybe something more like:
Smart, KO, #16, Dallas 1st rounder, Brooklyn 1st rounder (their choice)
Noel, #3