Sorry, the part about the king staying in power. I'm sure his knights are plenty capable of dealing with non-Fairy Tail guilds.
Ahh, well i would say that atm it seems like the top 4-5 guilds alone would be enough to at least put preassure on the Kingdoms military (cant imagine any number of knights would be able to do anything against Jura or Rufus to start with).

And when there is such an imbalance of power, then i would say the King is only in position because the guild masters let him stay there.

Though i am also wondering about how Bluenote fits into all of this, it was said he used to be in the military, and he was a hades-class wizard, so why dont they have more people on his level of power, was he just a fluke?