The problem with that particular example, is that teams rarely trade for draft picks before those picks are on the clock. So if the Pats are trading two 4ths for a 2nd, it's the 2nd round pick happening after they've theoretically traded up in the first.
Now, they could trade THEIR 2nd to move up, then use two fourths to trade back into the 2nd for a guy they like. So perhaps I'm just needlessly arguing semantics
Either way, I think a 3rd in 2022, by itself, would be worth more to this team than a 4th in 2021.