Sure, smart guy. A good WR2 more often than not is someone who lines up against the other teams CB1 and reliably moves the chains. Pretty simple. A WR3 struggles against top tier corners, generally.
The next time Josh leads Diggs on one of these wide open deep balls, where he has beat his man, will be the first one I can remember. I may have forgotten some where Diggs didn't have to wait or come back for it?