You forgot Steve Johnson, Kolby Listenbee, and Dezmin Lewis. There are 9 of them, not six.
According to ProFootball Stats whose records date from 2007 here are the total numbers of WRs drafted for each team.
Atlanta - 5
Buffalo - 9
Carolina - 7
Chicago - 9
Cincinnati - 15
Cleveland - 11
Indy - 7
Arizona - 8
Dallas - 6
Denver - 6
Detroit - 8
Green Bay - 10
Houston - 11
Jax - 11
KC - 12
Miami - 12
Minny - 11
NewOrleans - 6
Pats*** - 10
Jints - 9
JESTS - 10
Ten - 10
Philly - 8
Pit - 11
Oakland - 11
Rams (STL/LA) - 13
Ballmore - 12
San Diego - 5
Seattle - 8
SanFran - 9
Tampa - 8
Washing - 11
That's a total of 299 receivers selected in the ten drafts from 2007 though 2016.
That's a League average of 9.3 WRs taken per team over ten years.
The Bills picked 9 WRs in those ten years.
You were saying?