The ability of defenses to slow down the underneath stuff is going to be dependent upon Coleman’s development and Cooper’s ability to integrate into the offense. Keon has already shown the ability to break a tackle and turn a hitch into a splash play, and he’s shown he’s capable of getting open deep on scramble drills. The whole league knows Cooper can get open deep, so he’d have to prove otherwise.
That said, I wouldn’t be surprised to see Shakir start putting up career production that’s somewhere between K Allen and R Cobb if he stays relatively healthy. In other words… a guy that consistently sniffs a thousand yards, has the ability to have monster games, and goes over 1,000 yards 3-5 times. Shakir’s yac ability and catch percentage make him a serious problem for defenses.