Battania has fairly crappy troops, apart from the noble line, and hands down the worst location in the game. They ought to be pretty safe, up in the mountains like they are, but their castles are the wrong places and enemy armies can just march through the passes.
Come to think of it, none of the castle placement makes a lick of sense. You'd think that choke points, passes, bridges, and the like would all be fortified. For instance, in any rational world there'd be castles at the chokepoints between Aserai and Empire territory and between eastern and western Sturgia. Those are natural places for tax collection and defense. Add in a mechanic where only small bands can slip past defenses to raid (which would therefore be dangerous, as it should be) and the world would be a whole lot less chaotic. That would make for stronger economies, better armies, and wars that were more than random, unfocused dustups.