Garrison and Keep Expenses
Now these are a little different in regard to money. One can think of them as an all or nothing expense. These expenses are for the defense of your fief. Thus if you have your fief you get all the surplus, if you don't have the fief you don't get the money.
These expenses are tough to say what is best and what should be spent on them. This is the advice we offer - When not at war set keep at 8 times the population of the fief. When at war max your keep expenditures.
These are normal conditions unless other circumstances warrant changes. If you're having a hard time increasing loyalty, then spend the maximum amount on the Garrison.