Nearly all the information in this thread is wrong :)
just give us out the right answer! :P
i did play a lot around single player and bosses, but i never got to read the script lines behind the ai bot. so i am simply stating what i know from my experience.
the ai will move the boss as a first order, to a random spot.
the randomness has some specific criteria rules, but if all territories are conquerable the ai will just randomly attack one with the boss