He can make us a lot better, yes. But it's also true that this group needs time. The championship team didn't need a ton of time but those additions were KG, Ray, Posey and House. VERY specific roles they all had. Adding Lee, Terry, Green, Sully, and so on is a whole different thing.
As others are saying Doc needs to figure out his rotations too. When Avery comes back he knows he can trust him. If you throw out KG(28), Bass(28), PP(30), Avery(28), and Rajon(38), well, we have had those starters together before. And they were a very solid group. We know that works. I have left 88 minutes for the bench and between Lee, Sully, Green, Terry and Barbosa, 3 or 4 of them have to take turns coming through. But as bench guys coming in for my starting group their rolls seem clearer to me: Leandro and Terry need to add scoring; Sully needs to board and do the little things; Lee has to add big d, run and hit some corner threes. Green needs to run AND PLAY HARD D ON WINGS and get PP rest. Whether they can do their rolls I dunno but those are their rolls