I think I would do that. It's a lot to give up, but you're getting a lot back. I think Peterson is a huge upgrade at the RB2 spot, and Cooks has been good enough lately to make me feel good about giving up Dez. Like I said, it's a lot to give up, but I think you're in good shape with the roster as you have it, and I think it's worth the risk of dropping a WR.