It's a new team with new players, a new HC and OC so a ton of change for any starting QB. We don't know what would have happened this year with the Browns if they didn't draft the best QB to come out. Mayfield is better than Tyrod. Tyrod is better (right now) than all of the Bills QBs. He'd have the same receivers, HC, OL coach. Basically the same team and environment with the only change being OC. He'd also have a better kicker and If I remember the Kicker missed the GW kick in that 6 TO game.