to digress slightly , the best accompanying guitarist i have ever played with and that includes some well respected professional players, lives close to me in ireland, uses standard tuning, but actually listens to how i am playing and is familiar with the tunes before he accompanies,guitarists if you are accompanying learn to sing the tune first, then LISTEN to the melody player you are accompanying, it is not just about getting the chords right.
Quite frankly, I would rather not have someone strumin if they cannot get the pulse right and if they are just filling in the sound, what i want from a guitrist is someone who can lift the tune, not just fill in the tune, nor do i want some idiot who plays hornpipes without any swing but tries to play them like reels when i am trying to swing them ,it just becomes a battle.