You guys do know the land your people have taken is too big, right? If anything, a viable kingdom would have all settlements more or less close to each other, for ease of trade and stuff. With the current human population, most human societies would only have territory as big as mere hundreds of square kilometers. I see kingdoms with thousands. So are traders expected to take unkempt, dangerous roads from a huge city to a small village of 20 and expect to make profit? I don't think so. That eliminates internal trade, which in turn eliminates news traveling from place to place, and in turn eliminates technological and magical advances from going beyond the town in which such advancement was made.

The only ones capable of expanding as much as they have are the dragons (because of the speed at which they travel) and the Cimex (because of their numbers and absolute industriousness). 

To become a truly defensible (human) kingdom, you need towns, and towns house quite a few thousand people. And let's assume a town has a easily defensible radius of 150 kilometers. You could have two towns and a dozen small villages and you still wouldn't have a quarter of a continent as your kingdom's land. Sure, you could [i]claim[/i] the land, but you wouldn't be able to defend it. 

Believe it or not, sending a medieval army a thousand miles away from their supply point hoping to defend against an army is just going to end up with half of their numbers being supply wagons (filled with food needed by the people back home, who'll starve without it). Enough to say that's not viable when you'll be fighting hordes of vicious Cimex.

But that's just my take on it. Kuro himself has about 1.000 people in his settlement, and he can't even call it a town yet cause he has no walls and no numbers.