I don't disagree that they need production, but a 3rd edge is less efficient for a team with a lot of holes. Turning him into an impact player elsewhere... say a WR, TE, or RB, will help revamp the team... or play it smart and get another lineman. I get those 3 edges would be good players, but its diminishing returns if you can't have them on the field all the time. I think an extra offensive piece is important if they want Shadeur too.
Main problem is that I don't believe he's only worth a 3rd. My guess is he'd at least get a 2nd. That changes everything cause then the Giants can really make good use of that trade. If I were a Giants fan though, I'd not want to lock up so much in my edge position. They'll get more on the field impact by moving him imo. I'd like the rotation if they were a good team that could afford the luxury to not maximize their talents.