Mick is quite correct to say that GDAE is "mandolin tuning", obviously, and of course the reason that can only work so far as size and scale length increase, is that the mandolin's short scale length makes various chord fingerings--particularly four-note, closed position chords (no open strings)--playable that your fingers can't reach on a longer-scale fretboard.

But hey, I'm a mandolin player, so sue me, ya big galoot. That's why I got a "long-necked" octave mandolin.

What I'm wondering as all these tuning acronyms are bandied about, is: do REAL bouzouki players, who actually learn these different tunings, play fiddle tunes with them? Or is it mostly accompaniment? Who's particularly good? (Any youtube suggestions?) Because of course fiddle tunes are generally composed with GDAE in mind, and adapting them to other tunings is challenging.

I might give GDAD a shot. It is of course just a slight variation on the holy quartette of fifths, the peerless and unmatchable queen of tunings, GDAE.

W-O