I don't know how much I like the Simmons comparison simply because I feel like it is far more fitting in favor RJ. Zion has a really nice handle but he doesn't seem to have the knack for finding passing lanes to teammates in the same way that Simmons and RJ do. He's an attacker, he gets the ball, uses his first step, lowers his shoulder and gets to the paint where he has a great touch with his left hand and almost no touch whatsoever with his right.
I agree with Adam that his deficiencies in his game are pretty glaring but you also kinda put up with it because you would legitimately have top 5 percent athlete on your team. The potential is so tantalizing that even though the jumper is beyond shaky and he doesn't have much in the way of a varied offensive game, the fact that his handle is a solid as it is and his burst and explosion off the floor is so otherworldly kinda makes it worth overlooking those issues at least initially.
Like I said earlier, I still consider him to be a tier below RJ and Nassir but the upside he has is unbelievable.
The semblance between RJ and Simmons is that they both are fake lefties and have an awkard and unnatural shooting stroke. RJ, like Simmons is right handed, and yet he shoots with his left. I would be very wary of his shooting tbh.
You say that Zion is the one with the glaring deficincies, and I would actually argue that RJ is the one with the bigger holes in his game when you look at what they will have to show at the next level and what you want our of your superstar wing that doesn't have any elite size or athleticism.
Even this early, I can clearly see how Zion will get his production. At the next level he will still be quicker, more explosive and bigger than everyone else. He will be able to play 1-5 and exploit most matchups.
He is not just an atheltic marvel...he has real skills. He is not less skilled than Derrick Rose at Memphis.
If Draymond Green manages to be a plus on the offensive end, then Zion who is better than him at everything on that end will surely be one. Imagine this fucker grab a defensive board and go coast to coast...try stopping that. Zion at Point-Center will be a cheat.
He has a better first step and is more explosive than Lebron when he first came into the league and he weights in at 285...sheesh. Lebron actually got more explosive in the NBA, specifically in 2009...so we can only imagine.
Now for real, I don't see how you can put Nassir a tier above Zion. To me at least, he is a tier above both of them.