Take mayfield and rosen, then trade one next year!
Why when a player like Barkley or Chubbs will be sitting there?
Take advantage of capspace and draft capital to double your chances of hitting elite status at the most important position to anchor your franchise for 10 years; keep the better one; still trade the other for a bonanza given the market for competent QBs. Let's say the lesser one is a Jameis Winston/Mariota type; that player on a rookie contract with just 1 year of the rookie contract completed would be worth a lot.
Except the QB's value will likely drop after losing out and not playing. (not to mention neither is likely to start this year)
And the value you trade for is not going to match the value of the 4th pick this year. There will be other new shiny QB to go after at that range.
They won't do it, because every team thinks they are the best at evaluating QBs. But it is an interesting though. The QB position has a far outsized importance in the NFL. A franchise QB can be there 8-12 years, which is, what, 3-4 roster turnovers in the NFL? Outside QB, roster rebuilds can happen.
So I'd think that a highly rated prospect who has 1 year of bench learning is still a valuable asset. Not #4 pick valuable. But still valuable, maybe a 2nd and 3rd rounder. And you double your chances of getting a great great QB for 10 years.
So, would you trade #1 and #4 in 2018 for, say, Rookie Andrew Luck and a 2nd and 3rd rounder in 2019?