The role Coleman fills on THIS offense would not be filled by Worthy. X MUST block and block well (see: Davis, Gabriel and Hollins, Mack). While receiving is 1A, for the Bills, blocking on the outside is 1B. If Coleman can be 80% the blocker Hollins is while simultaneously being 80% the receiver Worthy is, that's much more important to this scheme than one OR the other.
People are also forgetting Coleman just turned 22, which is only a couple years older than Edmunds. Talking about him like he's reached his ceiling, I'm not on that train. I feel 75/25 that he surprises to the upside this year, especially if he gets a few more calls when DB's are pogey'ing his jersey that he didn't get as a rookie last year.