Defending a castled province without patrolling?

[archaeolept]

there'll only be pop loss if there is unrest. unrest is reduced through lowered taxation before it is through patrolling, i believe, so lower the tax rate and you should be fine, unless you have very high levels of unrest.

and if your tax rate is already 0, for instance because it is a bloodhunting province, well then, just suck it up and either patrol or don't.