Well this is interesting.
I'll take a stab at how the band member's IQ always came off to me. Not really based of each person musically.
Lindsey Buckingham
John McVie
Bob Welch
Christine McVie
Rick Vito
Mick Fleetwood
Bekka Bramlett
Billy Burnette
Stevie Nicks
Peter Green
Danny Kirwan
Just how they come off to me from what I've heard about these people.
We don't really know for sure.