Caliing out JC is fair, and Sexton also gets the full benefit of better spacing with Lauri and uses it as his usage goes up by 1.58% when he plays with Lauri.
I also agree that when Keyonte started the year facilitating more than shooting it was more beneficial to Lauri, but I also thinks he is largely collateral in that equasion. His own usage drops from 22.6 to 19.2 when he is on the court with Lauri, so he definitely defers more when playing with him. The bigger problem with Keyonte is that he is too quick to defer to Clarkson, who then "does his thing". JC usage with Keyonte goes up by 1.91% and the other two main beneficiaries from Keyonte deferring are Kessler (+2.05%) and Fontecchio (+2.66%). Kessler is a great sighting on that list, but neither JC or Fontecchio should be ahead of Lauri in the "pecking order" of who you pass the ball to.
So if Keyonte wants to be a good NBA level starting PG he needs to understand who the best player is, and prioritize getting him the ball. He defers, but to the wrong guy(s).