It's apples and oranges. The Pats get a net gain in cap space (maybe not great, but it's there) swapping out Jones for Cooper, at a time they need cap room to sign more critical defensive players. Whether Cooper is any good is a separate piece.His cap hit is $3.5M which is not nothing. Knowing that the Patriots put a pretty high value on $3.5M in cap space, I would think that they see something in Cooper -- they're not throwing away $3.5M in cap. I also assume that, given his draft status, Cooper was of some value on the trade market. Therefore if the Pats didn't see value AZ would have been better off trading him somewhere else. Clearly the Pats saw some value.
Either that or the consensus on Cooper is that he's not worth much and the Pats are just taking a flier on a guy they can always cut. I'm guessing this isn't the case but you might be right.
Field Yates @FieldYates
For the Patriots, this trade clears $5,410,045 in cap space for 2016.