GRIII is intriguing. I believe in the 20 year theory. That is, if you do something hard for 20 years at something you can become an expert in your field. GRIII is nearing the 20 year mark due to growing up around basketball. Plus he has a ton of skills. He can be a good backup option if Jordan Clarkson leaves.
The only big downside is that it takes Niang's insanely hot shooting off the floor. I am not sure I want to do that. But the perimeter defense in the 2nd unit would improve.
Niang is only insanely hot some of the time. The rest of the time, his lack of defense and rebounding are a problem if he's not on the floor with Rudy.