I would take Ernie and Bernie over any I have seen at Tennessee. Williams is the best player on this squad at this time. He has moments of greatness, but slips back to just a good player. If he continues to improve, he may not be around for his senior year.
I love Grant Williams as much as the next guy, but no way does this happen.
Williams is a PF. The average height of a PF in the NBA is 6'9.4". SF is 6'7.7". SG is 6'5.3".
Williams is listed at 6'5". So if by "continues to improve" you mean becomes much faster, develops great ball handling skills, and becomes a dead eye shooter, then he MAAAAAAY be able to sneak in as a small forward. But right now his game is almost entirely back to the basket hooks and layups with some turnaround jumpers. His 3-ball is better than last year but has a lot of room for improvement. And that's just on offense. I don't see him being able to play defense on much quicker, slimmer SF in the NBA. He just doesn't have the speed for it. He does a good job defending taller PF in college, but I don't see it translating to the next level.
All that being said, I think GW is going to be a really great college player when it's all said and done. He's just genetically restricted at the next level. If he were 4 inches taller I'd say he'd for sure get picked.