Following up on what Fortunato said, Don Reno developed a slightly different style of picking using single-string playing alternating thumb and fore-finger like a flat pick. As a result, his style would be more percussive than Scruggs. He was in the army, I believe, at the time of Earl's popularity and was probably a little up-staged as a result.

I think Bill Keith deserves some recognition for taking the bluegrass style in a slightly different direction with the "conjunct melody style".

Also, Bela Fleck, Pat Cloud and the more jazzier approach varies from Earl.

The most remarkable thing about Earl is when you slow his records down, his timing is consistently impecable. Slow down some other players and you'll see what I mean.

I met him in the Fifties with Guy Carawan and Jack Elliot, and he was the nicest person.
I think his humanity was equal to his talent.

Frank