‘...when it comes down to it probably the best two popular guitar players of the 60s-70s were Glen Campbell and Roy Clark.’
both were astoundingly good pickers; I always thought Campbell was just a media creation (Rhinestone Cowboy,ugh) until just a few years ago when I saw a video with him playing...and Clark was the best, simply the best...
I thought you were going to mention Chet Atkins. Both Campbell and Clark came from him.