Well like I said before, as long as our established group can claim some territory to form a base it would be cool to duke it out to annex all of it eventually under the Shinra umbrella! But it seems you are wanting to separate it from contact outside of its own self contained world. So that might not work out to well. I think it's where we see things as "omniversal". The omniverse is everything...every single multiverse and realty is linked somehow to others and is under the broad term of omniverse. Which is basically just the infinite worlds, universes, and multiverses of every single story/world/posibility that ever was or ever thought or will be thought. Its kinda trippy...but pretty simple. Basically the "world of war" is just another component to the larger Omniverse. But it also makes the world of war very possible because there would be omniversal beings that could span from multiple multiverses that got together to create an artificial one. So yeah its totally workable as an idea. The downside is that we keep our characters in a certain timeline, and we cross over into other places. Having some duplicate over in that world doesn't help with that or push us forward in terms of story.