It's the same scheme and Haskins put up better passing numbers in that offense. Please tell me more about Fields being clearly the better passer.
Sure.
Looking at 2018 Haskins vs 2019-20 Fields (so giving Haskins the benefit of the doubt by only using his elite season).
Haskins had his numbers padded on short passes. 24.2% of his pass attempts were at or behind the LOS compared to Fields. If you weight completion percentage for air yards (adjusted completion percentage), Fields is at 77.8% compared to Haskins at 73.1%.
Fields converts 1st downs on 52% of the time on 3rd down compared to 45% for Haskins.
Haskins also had a better supporting cast. McLaurin and Campbell were both Day 2 picks, and Austin Mack is playing in the NFL, too. Olave is a pro. Garrett Wilson might be, too. Fields has also been pressured more often, so the OL might not be as good.
Fields also had a better Total QBR and a better passer rating than Haskins did.
Fields also has more career touchdown passes and fewer interceptions on fewer pass attempts. And he averages more yards per attempt. Haskins' only edge is in completion percentage (70% to 69%), and that's padded by his short passes as I mentioned earlier.
Where are these "better passing numbers" that you speak of?