I wouldn't give up on Young yet. He had some dominant games int he D League last year and the talent level there is a little better than Summer League.
AB on the other hand is a known commodity. Good rotation guy, probably good enough to start on a few teams. But he's not good enough to be a real difference maker. If you could make a deal to upgrade one of the front court positions, I'd move him. But if not, he's OK here - at least till someone else proves they deserve his minutes.
Toss Livingston, Young or Hunter in there for him right now and you're downgrading the team quite a bit.