This would make sense as we've seen Alexander diametrically opposed to Bahamut in the past (ff9). It explains the dragon hunting easily, and Alexander could easily BE Ishgard.

Odin and Atomos bring up a few different questions though. From what we know, Odin will be a wandering primal gaining power not necessarily through the Aether, but rather through repeated defeats. His relationship to the story will be interesting.

Atomos, well I have a tin foil hat opinion on that. Atomos is frequently associated with space and time distortion (and gravity from the older ff games, although that role has fallen to Diabolos recently). I believe that it was not only the defeat of the primals but the appearance and actions of Atomos that prevented the re-sealing from succeeding. From my vague recollections of FFXI WoTG, atomos was used as a time travel device to prevent a chain of events from occuring. Now, could Atomos be sentient, and possibly wish to break the cycle of Astral/Umbral eras? In fact, upon further thinking he himself could be responsible for the cycle in the first place (had he not acted, the lands aether would have been richer, possibly leading the re-sealing to have been successful).

Yoshi-P certainly guided the story around many interesting topics. We have the fate of the GC companies, the march of Garlemald, the beastmen, the primals, Bahamut, and Atomos to worry about. They have enough interesting storyline options to design high level content around for at least an expansion or two.