Overthrowing foreign city with culture

[danceswh]

Just after some friendly advice.
I'm a long time Civ IV fan, and currently use the Bat mod, which is really nice.
I'm a fairly average player skillwise, so please be gentle with me lol.
One thing that always frustrates me in a game is that no matter how much i spread my culture, trying to topple nearby cities and get them to join my empire, they more often than not, don't switch to me.
They seem to survive forever, even when i have 60+ culture, and no matter how many times i send spies to unsettle them.
Am i missing something, or is this just 'how it is' ?

 

[AcaMetis]

Military units stationed in a city decrease the chance that a city revolts and flips. If AIs aren't at war they will station their armies in border cities that are being pressured culturally to prevent them from flipping. Religion also plays a major role in terms of flipping cities - a city that has your state religion is more likely to flip to you, whereas a city that has it's current civ's state religion is less like to flip. If both are true the modifiers cancel each other out.

 

[danceswh]

Military units stationed in a city decrease the chance that a city revolts and flips. If AIs aren't at war they will station their armies in border cities that are being pressured culturally to prevent them from flipping. Religion also plays a major role in terms of flipping cities - a city that has your state religion is more likely to flip to you, whereas a city that has it's current civ's state religion is less like to flip. If both are true the modifiers cancel each other out.

Yes of course...the military units in an AI city does make sense actually, and explains why in my last playthrough the AI filled its city with troops but never ever attacked me...which is what i was expecting.
Many thanks for your help friend