Actually we do have a couple of trade-down options, assuming the Pats think McCarthy is on the same/very similar tier as Maye, making it a top-4 QB decision. Assume for this discussion that Caleb and Daniels are taken at 1 & 2.
a. move down to #4, swapping with the Cardinals who pick Harrison. Would have to convince the Cards that we were gonna trade #3 to someone like the Chargers who'd take him. If the Cards really love MH, they have to be worried about this scenario. This would be the best move because Maye and Daniels would still be there for us at #4. Even if AZ surprisingly trades the pick or takes a QB themselves, we're still getting one of the 4 top QB's at #4. And AZ has a ton of draft capital including #27, which I'd love to swap for 34 as part of this deal. We should be able to get to #27 plus get one of their three 3rd rounders.
b. move down to #5, swapping with the Chargers who picks Harrison. AZ would then likely trade down from 4 to a QB needy team who takes Maye or McCarthy, then we take the other one at 5. We could discount the price in this deal (e.g., get their 3rd and 4th) in exchange for assurance that LA must take Harrison and not trade it or take a QB with the #3 pick.
Either of these moves would be extremely desirable for us, where we get to eat our cake and have it too.