Smash combos were designed to be zone coverage (though it's not like it's a bad route combinations vs man). Forces the CB to make a decision. If he drops back to the corner, you hit the curl. If he stays tight on the curl, you throw the corner. If the corner comes up on the curl and the safety overplays the outside taking away the corner, you need to have a TE or RB out of the backfield hitting the seam.