No, the AI will spam actions based on the knowledge of forces marching on them from far away. I get what you're trying to say, that it only "sees" these stacks when being marched upon, but experienced players have used this to get it to "cheat" and lift sieges or combine stacks into attrition through the fog of war and cripple its siege progress, melt its own stacks, or lose because they or their ally got sieged first and suddenly one side is the player's vassal.
On sea, it's less abusable, but on land you can definitely make the AI screw itself over without the inconvenience of ever having to actually move.