And you may be right. Certainly you're right that he's not the athlete Wilson is and he doesn't have Favre's arm (tho his arm seems stronger than Garcia's was). But as I said, I've never seen someone who can throw the ball so accurately downfield while moving. Does that trait alone guarantee success? Definitely not. But I think that trait, coupled with his high processing speed (his analytic test scores suggest some of Cossell's analysis is misplaced) and his desire to be the best will vault him to stardom.
Then again, I am no expert evaluator. I just go by my own eyes - I saw Mayfield destroy good defenses over and over again, it looked almost effortless, and defenses who tried to move him out of the pocket paid dearly for it.
Also this:
https://sports.yahoo.com/news/greg-cosells-nfl-draft-breakdown-accomplished-deshaun-watson-has-areas-to-work-on-164552341.html