After a very large number of gameplay hours without FOW, I come to the conclusion that non-roman AI factions do not effectively invade roman AI territories regardless of their vulnerability.
They will ineptly defend their own and engage in naval warfare, but they will not take a roman settlement even ungarrisoned.
At the same time revolts will not occur in roman AI settlements even when at less than 50 loyalty for many consecutive years.
Is there something to do to modify these two annoying features ?
The first one is very important because it has a huge influence on how a world will evolve, especially in a modded alternative.
Imagine for example in the warhammer mod, the chaos factions respecting the territorial integrity of the factions with the roman culture tag....

Magussen