is it possible to fix this problem by increasing settlement's unrest when only few units guarding it but not the garrison scripts?
I saw that sometimes after AI crusaders captured Jerusalem they won't go on to attack other nearby enemy settlements but stay in Jerusalem to maintain public order. i guess it's not realized by scripts.
my point is that even in a faction's capital city with 100% religion conformed they will still need to put 4 or more units (depends on the population) to guard it or the public order will be in a riotous level. let entertainments and tax rates has smaller effect to public order while garrisons scales more.
so the garrison scripts will nolonger be needed and the waiting time between turns will be shorter.
but probably it will affect a lot of other features and change the game experience totally. it's just an idea.