I don't really see Deng's skills being less utilized in Vinny's offense than Skiles' offense. I think the difference is that
1. Luol Deng was forcing offense this year. He would get the ball, pump fake like 20 times, and then throw up a bad shot. Under Skiles, he let the offense come to him.
2. Luol Deng is just missing his jumpshot. In 2006-2007, his one really good year, he was automatic from midrange.
Check out this graph.
FG% is what to watch for Deng. If he shoots the ball well, he's useful on offense, if not, he doesn't do well.