Well, there is one part of FFVIII that is never satisfactorily explained (in my opinion) that could lead some credence to this idea. You hear about the Lunar Cry that happened in Centra (Centra-Cetra... More cross referencing ) and wiped out everyone on the continent. That's all fine and dandy. But where did the huge crater in Trabia come from? If you try to fly the Garden into it, you get a message very similar to what happened if you flew the Highwind into the crater in FFVII while Sephiroth's barrier was up... And Trabia is the northern continent. If you allow the continents to change shape somewhat as time went by, it could be the same world. I personally don't believe it is the same world (you'll have to do a lot to explain the switch from Materia to Junctioning... And what happened to the Lifestream or Mako?), but I do want to know just where that crater in Trabia came from...