[archaeolept]

the value of a unit as a patroller is related to the sum of the unit's AP and prec, iirc. However, there is a random factor as to how much of the unrest they actually keep down.

mindless aren't very good or are useless. animals may have a negative modifier.

also, some units have a patrol bonus.

Move and patrol reduces unrest sometimes... i'm unsure exactly what happens.

As well, it is important to remember that the income reduction due to unrest occurs before unrest reduction is determined - so, if you set taxation to 200%, you will lose part of your income due to the unrest before your patrollers remove it. ie., there is somewhat of a diminishing return w/ overtaxation even when you have sufficient patrollers to keep unrest under control.