With all the width we have added this summer, 1 of our front 2 will be a striker who is strong in the air (Amauri, Trez, and to a lesser degree IQ). The other will be a creative SS type player (Diego, ADP).
If Benzema arrived, it would mean 1 of Diego, ADP and Benzema would pair Amauri or Trez upfront. With IQ still here as well, we simply have too many players in attack, and I doubt Benzema would swap an uncertain starting position at RM witht the exact same situation at Juventus, albeit with possibly lower wages as well.
Considering all the cost cutting our management have done this summer, unless 2 of our forwards leave, I don't see us making a star signing upfront.