Do not like that fit whatsoever. You have to have a good defender next to him preferably with some size, but while Fultz has enormous defensive potential, he doesn't look very good right now. He's probably worse than Jaylen was when he first came to the NBA.
Ideally, I hope we sign Griffin in free agency, which will require us to probably trade Bradley for space. At that point, I think Brown should start at the 2. His improved defense and shooting make him a viable starting 2 next to IT, and it'll help him really develop. It also makes our starting lineup much bigger and more athletic.
Then I think Fultz and Smart should get big minutes off the bench, probably cutting down Skart's minutes a bit so that Brown and Fultz get plenty of developmental minutes. Brown should receive approximately 30 minutes next year, and Fultz should probably get at least 25.