User blog comment:Zathronas/Analysis by an author: World of Remnant, Kingdoms/@comment-25091485-20140919105856

Well, after hearing the Military part, the strength of the Atlas military (probably backed by the SDC)  and the conspicous absence of any military personnal in Vale, I do believe the only thing stopping them would be, of course, our main characters. But lets say if Atlas attacks, whats stopping the 3 kingdoms from banding together to confront Atlas? Maybe they will have their own problems? Maybe there will be a certain mis-communication?

We also know there are 5 distinct landforms, 2 of which are seperated from the kingdoms. I would think that's likely where a fair bit of the Grimm and Faunas are. After all, we do need a convienient storing space who the huge mass of Grimm that will swarm the kingdoms and of course those 2 landforms are convieniently pretty close to the Kingdoms (except maybe for Mistral) (And i do wonder how the land Grimm will get across)

(P.S. Thats a ton of Islands and narrow spikes of land)