Originally Posted by Blodrast
just get the generals off the stack and put them in their own stack; i.e., with no other units in the same stack with them.
This way, even if they do rebel, they might be the only unit that rebels.
The other thing is to try and create groups commanded by a loyal general, and put the other troublesome generals in the same stack. Of course, you need to have loyal generals for this in the first place ;)
A slight variation of this is putting the generals in your king's stack; the king is always the general of the stack he's in, so it doesn't matter how many stars your generals have, they won't be the generals of that stack; moreover, keeping them in the king's stack will slowly increase their loyalty over time (slowly is the keyword here).
Your peasant army: mostly useless, if you don't need it for garrisons.
For all army goups, though, as I've said before, try to create groups with a loyal general leading them, and fill them up.
The general of a stack is the one with most command stars (unless the king is in that stack, he is always the general).
If several units have the same amount of stars, I believe cavalry is favoured. Other than that I am not aware of any criteria for choosing the general (and believe me I have looked, because I have similar problems with low loyalty).
Btw, try some jihads if you can. They increase your influence, and in return the loyalty of your generals.