KD may have been luck, but was Westrbook, Harden and Ibaka? At some point you have to acknowledge that the man knows what he is doing.
He's no dumby, and he tries his best, like all other GMs, but he's not the talent evaluator and negotiating genius he's being anointed as, by some. He has his hits, and his misses. He didn't seem to "know what he's doing" when he signed Ibaka (great shot blocker, but what else?) to the big $$$, knowing he wouldn't also be able to keep Harden. Then gives Harden up for 3 bit pieces.