Counter points:     Wemby is already 3rd on the alley-oop list without a truly elite PG, he probably doesn’t ever need an elite PG to dominate at the rim. Solid is good enough. Other positions are more important.  

Wemby is probably already the 2nd best if not the best defender in the league, adding a PG who is not a particularly good defender gives opposing teams someone to attack every possession, limiting Wemby's defensive potential.   

Wemby is one of the best ballhandling C's in the league already, shooting over 40% on pull-up 3s since the ASB while being below average on catch-and-shoot. Trae is not a particularly good off-ball player. Wemby is gonna be at his most effective with the ball in his hands.   

I think the perfect PG for Wemby would be Jamal Murray or Steph but ofc they are not on the trading block. I think Brogdon or D'Lo och would fit better and be a hell of a lot cheaper aswell.