I've heard some guys say that he has poor mechanics and wonder if they can be fixed.
Guys as big and athletic as Wentz can often have really good 1st years....RG3 comes to mind. Problem is, these kinds don't usually last long because while it's the legs that gets them the highlight reels, it's the passing prowess that gets you better and leads to championships.
Not at all ragging in Wentz. He may continue to develop and be a very good QB. I don't think I saw him play at all last year, so I don't personally know. Just repeating what I've been hearing.
Goff is a much more pure passer, and accuracy has been a strong suit.