Will Chavez jr come in 30 lbs heavier then Cotto who is a natural welterweight?

Bob Arum is ducking maravilla and putting chavez up against cotto who is hardly a 154 fighter. the fight will take place at 160, and cotto will still whoop his butt. but how would all of that weight effect junito? will he be slow? and since chavez out weighed the natural middleweight zbik by 15 pounds and still got tagged how much do you expect him to out weigh miguel by?