
Originally Posted by
Leving
The reason why you can't starve them is that the AI gets hidden bonuses to food. This is because they are so stupid without such bonuses they would simply starve to death of their own volition. The same can be said of public order and income. Note that on harder difficulties the bonuses the AI receive are greater than on lesser difficulties.
Unfortunately this ultimately means that it is not possible for you to starve the AI via raiding or destroying buildings, but you can at least reduce your own costs using this method. Sadly there is nothing that can be done about this if we want to have a functioning CAI. Raiding often also draws the AI out from its settlements, though not always.
In your scenario, the only way you're going to be able to win is to gather another stack and siege with two. I would also note that Roxolani is one of the most difficult factions to play in the game. Your best bet is always to rush the Thessagetae at the start or you'll be financially unable to compete with the AI at all.