Thankyou JCB! I've noticed increased AI aggressiveness as well. Playing as Massilia, I'm rather taken aback by how rapidly Rome is advancing northwards, against those Barbarian hordes. I like the sense of progress this gives to my campaigns, and it also creates the risk of greatly over-extending your own lines, which I don't think is such an issue normally. The fact that armies can reinforce each other across greater distances is a very helpful feature for the AI. 0.
But it sucks that it only works for GC
Also, does this affect how far armies can retreat?