The problem with those realms is the massive refit times they will have to deal with in any war. And you really can't expect a realm broken in two to go to civil war with each other just to have something to do. That's a fake and lame war. Plus the fact that any invasion will have to be by ship, which gets expensive.
The southern part of Dwilight is unfortunately very bad geography without the western side of the continent. That big no man's land between Fissoa and Shinnen/Giask really makes it hard for anything interesting. If Irvington was a city it'd be a lot better. But Luria would probably own it.
