Elite WRs (think Larry, Dez, Brandon Marshall, Megatron) just don't seem to move the dial in terms of wins/losses the way you'd expect. More than almost any other position, <Good> players in quantity can do as well as <Elite> players.
My example for years has been Green Bay with Jordy Nelson, Cobb, and James Jones -- all of who would be really good #2 WRs on other teams in the NFL, however, I'm not sure any of them would be considered #1 type guys and maybe none of them would be ranked in the top 20 of NFL WRs. Altogether, however, they remove the need for an elite #1 WR.