Who does an army listen to? I'm reading Shadow Games (the 4th book in the Black Company series) and there's a situation where a General might be in a position to draft folk for an army, but there's a local religion to whose Priests these folk are loyal.
I'm think about forum mafia (http://newforum.droqen.com/index.php?topic=57.0), and how things can swing depending on who's mafia and who's not. What about depending on who really has the hearts of the people? It's something you might not know until it's tested, and the test might cost you dearly. (I.e. the General says "to battle!" And the Priest says "mutiny!")
Mafia writ large. An army a thousand strong, each conscript playing a game of localized mafia.