Truth be told, GS might be better off with Jimmy than KD.
There isn't that much difference in ability at their respective ages (not like it was in 2017); Jimmy's better at getting to the line (providing a better balance with their outside shooting); Jimmy's a better defender in almost every sense; Jimmy's better working out the post; and most importantly, they kept more depth, where they didn't have to give up Kuminga.
Dray and Jimmy together on defense has been incredible too. Dray hasn't had someone on that end of the floor he can play off for a long time.