No, Bretonnia is not governed by the consent of the people. Bretonnia is governed by the consent of the Goddess who chose Louen to be king. This is a theocratic monarchy. Unless the Goddess decides otherwise, the King's will is absolute.
We've had kings divinely chosen by the gods too. The idea of a Theocratic Monarchy is not a foreign concept I can't understand.
All I am saying, is that the nobles of Bretonnia have expectations in how their king will act. And if he doesn't act like how they think he should act, they, the nobles, can do many things in response. Yes the likelyhood of outright rebellion is slim.
But, they could do many other things to show their displeasure and lack of respect. Holding back on taxes and tithes, not lending support to Leoun's endeavors not directly linked to Bretonnia's survival, not lending any aid to him period.
Even then, I doubt one count's honor duel with the Emperor's sister will result in any of that.
But, as I said. It's not that I think he can't do it. It's that I think, Leoun might think angering a large number of his own people, the noble's who actually police the land and directly lead the peasant on the loose lands and whom are responsible for the lion's share of the mundane work that makes a kingdom run and
can make his life much harder if they decide to spite him for not backing the count's win, is not worth a battle or two, or some diplomatic conflict, or some other kind of strained tensions with the empire. As you said, Bretonnia and The Empire are rivals. There is blood split between them in the past. What is one more conflict?
To sum it up, it's about politic's not ability and that what Leoun
could do is not what he
would do.
Furthermore, that's the last I want to talk about this for now. I have my opinion on this and you have another. And neither of them are important yet. This quest hasn't even had a chapter not devoted to character creation and I don't want to start an argument about something that might not even happen.