Edelman and Welker were excellent receivers that they saw the potential in and developed into the players they became. I give the Pats full credit for molding those two into amazing slot receivers and installing an offense that caters to their strengths. Outside of those two the only outside threat I can recall them drafting was Deion Branch. Moss was already a HoF caliber talent when he landed in New England after quitting on Oakland.
Since then they have had nothing but misses in identifying Wideouts in free agency or the draft. Hogan, Sanu, Brandin Cooks, K'Neal Harry, etc.