You didn’t make a mistake with McCaffrey. They were force feeding him the ball. He was just bottled up by a front 7 filled with first round picks. The Niners don’t have a ton of talent, bit what they do have is a very good front 7. McCaffrey is going to be heavily involved and GREAT, especially in PPR. His usage dropped once the game was in hand. No need to risk injury to such an important piece. They aren’t holding every team to 3 points.
As far as that trade, I think it’s fine. Probably a coin flip. On one hand, I don’t love playing saints on the road, but on the other Cooper has more serious competition for targets.