Don't both games also reference Hyne the magician in some way? In III, Hyne is a character you fight; in VIII Hyne is a magical figure in the lore. I think you can only read about Hyne in VIII from one of the rare magazines (or maybe even from the Garden homepage or whatever it's called).

EDIT: For your reading pleasure: http://finalfantasy.wikia.com/wiki/Great_Hyne