It's more of a suggestion to your allies so they don't always follow it depending on where the front is. Small fronts such as invasion fronts are often places where the AI doesn't want to remove their battleplans from.

Of course, you have be the one in control of the provinces in the area for it to work at all... or else you have to set an avoidance rule against the actual controller of the area if possible.

Ah I get it now. i thought this works like the AI avoiding user frontlines, but rather the province controller. Thanks for clearing it up.

But there was an old version of AI avoiding frontlines before, way back when the feature was just a simple national decision. Does it work similarly as today? Because (correct me if I'm wrong) I remember AI's back then were not entirely merging with user front lines no matter what.

引用自 Garensterz：

Ah I get it now. i thought this works like the AI avoiding user frontlines, but rather the province controller. Thanks for clearing it up.

But there was an old version of AI avoiding frontlines before, way back when the feature was just a simple national decision. Does it work similarly as today? Because (correct me if I'm wrong) I remember AI's back then were not entirely merging with user front lines no matter what.

It is the same as before, except that now you have much more control.