https://youtu.be/kjS0A32jQvU
Noah has giant hands. 10 and 3/4" same size as Gronk. It doesn't mean your good at basketball, Brown and Tatums hands are on the smaller side for ballers.
Check the highlights of Noah and you see that the giant hands make a big difference for dunking on people.
Does he do anything but dunk? I guess Robert Williams doesn't do much else either. Vonleh seems to have the body and athleticism for the NBA. If he is willing to take his defense seriously, he should be able to make the team and be a decent insurance big. His track record for maintaining the drive to be an NBA isn't good but this Celtics team should be a good environment for him.
Coming out of college, I remember he envisioned himself as a stretch 4, and I believe went so far as to tell teams he wouldn’t play center. But he was never very good at shooting threes, so if he’s learned he should be a center and just dunk, that’s actually an improvement!