Okay, this arguments about "what's realistic" is a dumb argument and I've said before the world must stay internally consistent not tied to a reality it isnt part of. But even if we're playing the "well in our reality...," even if we are playing the single most cynical desperation, the reason TT and Persian league would throw a fit at the hedgy-boys playing total war is because if they are willing to do ti with me, they will do it with them to. No one wants total war.
But as I said, throw the thematics aside. In gameplay pushing the player to fighting a constant wave of forever war endlessly because the hive of AI will keep punishing you for not engaging in blind total war is not a fun or interactive experience. It's a forced rush with an inevitable conclusion you fight back by chucking a single thing at it, money, until you get board of it and give up into forever war.