I've been worried about his defense for a while now - I thought initially it was because of the offensive responsibilities he had but I'm starting to think that being a negative defender is who he is. The two biggest differences between a Lavine trajectory vs Middleton trajectory are defense and playmaking, and we'll see how much he progresses in that regard. If he's stagnant, then I'd think about moving him at the end of the season especially if he has a very good and efficient scoring season - a 24/4/3 season on efficient shooting might be able to get you Lauri if you package it with a 3 nice first rounders with swaps, since a young efficient high volume scorer on a reasonable contract will be a very appealing asset to the rest of the league that Danny can flip into further assets.
Get yourself an attacking guard (Jeremiah Fears my personal preference) in the draft, and now all of a sudden on offense you've got two attacking guards with size (Fears+Castle), two supersized wings who can shoot at high volume (Wemby + Lauri), and a mobile center in the dunker spot who does all the dirty work and rebounding that nobody else wants to do (Sochan). All of a sudden the lineup makes sense as you add rim pressure without sacrificing size or shooting.
On the other end, you've got a credible way of playing Sochan and Castle together to add perimeter defenders to Wemby's rim protection.