He is productive indeed and he is not our major problem. He is a great 4, but we need strong 5 beside him and that's what I'm rooting for. As a trade asset, he's strong as well.
The thing is that he's not a great complement to a strong 5. KO, with his better range, is actually a more complementary player to the strong 5 that they need.
Sully is great scoring against average frontcourts and at just hanging down low to collect defensive boards. But he's mediocre on defense and he doesn't stretch the floor the way you need at least one of your bigs to stretch it.