Not mentioning Maybelle is logical, since she was really a precursor of modern flatpicking than of fingerpicking, even though she played with fingers and a thumbpick.

Some variation of the Carter lick - pick a bass note on one, rest (or hammer on) on two, downstroke on the trebles on three, lighter upstroke on trebles on four - is used for most country and bluegrass accompaniment with a flatpick.

Peter.