I believe that Ryan Nassib has received undo criticism. Despite the fact that this is a very weak quarterback class, many commentators have raised an extremely high bar for the few prospects that have a snowball's chance in hell of making a significant impact at the NFL level.
The top five QBs are all in the same boat in my opinion. None is head and shoulders above the rest, and each has a "flaw" that could hinder his jump to the pro game. I am not sure that this is a death-knell for any of them.
But I do believe that Ryan Nassib will have the easiest time adapting to the right system. He does a lot of things well and, without a strong supporting cast, improved his game each year that he played for Syracuse. The same cannot be said for all of the others in his company.
With the right coaching and support, Nassib has the tools to excel, including a good football IQ, good mobility, and the ability to make all of the throws asked of him.
This is why he will thrive in these programs...