I think Lawrence is more likely to "bust" because I don't think he reaches the Peyton Manning like expectations people have on the guy. I think he'll be a good QB at the next level, but I just don't think he's at that Peyton Manning level.
I'm not sure any of these guys will bust, tbh. All 4 of the guys at the top are special talents. Mac Jones is probably the most nfl ready but I expect him to be just okay.
Like you said, I won't be shocked if Lawrence fails to meet expectations. A lot of being an nfl qb is the situation you get drafted to. Fields has a luxury of talent around him, more than any of those top 5. He should have the easiest path to success, hopefully.
Kmet, Graham, Monty, Cohen, Damien, Arob, Mooney, Miller(If he's here still) are all legit nfl players.