I think Sullinger is a player who will come into the year in shape and play well. I don't think we should deal him now, because his value will be higher at the deadline.
If we are going to deal for Gallo, I don't want to give up a ton because he's a free agent at the end of the year. Danny said that he isn't going to make the team's talent worse in order to clear up a log jam, so I'm confident Danny won't give up a ton for Gallo, when they could go after him next offseason.
After giving it some thought, I'm fine with the roster we have now. I think one of Zeller and Olynyk will get squeezed from the rotation early, but there are always injuries in the NBA so everyone will get their chance. With Johnson/Lee being older maybe they will give them days of rest off where the guy squeezed out of the rotation will shine.