No it doesn't, especially if he can develop a three-point shot. He's becoming their lengthy/versatile defender who will match up on the other team's best wing player so Westbrook and Durant don't have to work hard on that end of the court. If he adds a moderately reliable three-point shot, he becomes even more valuable when Durant is on the court. Lamb will take some of his minutes when he's healthy, but he's going to play a lot for them.
Yep. Dre needs to become a defensive stopper who can space the court on the offensive end so that KD and Westbrook can do their thing.