Fields is a lateral move for either of those teams. He's statistically indistinguishable from either Picketts or Ridder.
It's going to be tough for Fields to find a guaranteed starting job next year. He's probably (barely) one of the 32 best QBs in the league, but he's right at or below the imaginary Dalton Line, where if he's the best you can do, you'd rather just roll the dice with a rookie.