Gallinari off the bench (soaking up all of Jerebko's minutes) and being a legitimate go to guy that can get to the basket, draw falls, and spreads the floor would be ideal. Or you can plug him in as the starting 4, having Crowder taking the harder cover, would also work.
As for his defense, per numbers he's good in isolation, but struggles in PNR. The PNR could be much improved with the way our guards fights through screens, though.
He was best in isolation circumstances, and was in them nearly 15 percent of the time. Opponents averaged just .77 points per possession in isolation and shot just 37.5 percent against him. His length was his greatest asset there, because Gallo’s first instinct is always to give ground in order to not get beat to the rim.
Gallinari struggled in in pick-and-roll. Whether he was guarding the ball handler (where opponents shot 47.4 percent), or the screener (where opponents shot 58.7 percent), he did not do well. He was easily screened in many instances, and late out to shooters as he, again, sank down in the lane and relied on his length to harass shooters.