Declare? Too lazy, I thought it was obvious I was not with the Overlord. Dare I raise my armies against him? I don't agree with the guy but I don't think he should die. 

Enforced abstinence? No, just no alcohol. If we had alcohol, there would still be riots. Drunken fools ans mad fools aren't that different. Having alcohol 'may' "improve" morale, but it makes it easier for them to rebel and have bad training. 

FLOOBY SOMETHING LIFE THREATENING I MUST SPEAK TO YOU ABOUT. 

It should not be required to have a full army stationed in a fief to keep its defenses strong. If it did, castles would be useless. If you have a fully stationed wall, even if it's 100 to a thousand, they should be able to hold out. Victory? That depends. But since they have incredibly high ground, are not fighting gravity as much as the enemy, and have ready cover (cover that is available automatically without being a distracted or extra work), plus other minor things that may inhibit the enemy in a substantial way, they should be able to have a fair fight