I think Coleman (X stater) and Davis (backup) both play a lot on offense - thus giving Allen a couple of new weapons to use. I could also see Van Pan starting by the middle of the season. That's potentially 3 offensive rookies from this draft contributing quite a bit. Not bad for picking at the end of each round.
Coleman, IMO, was a swing for the fences pick. There were safer options there, but he had the highest ceiling of all remaining receivers.