I dunno what happened. I'm Parthia in my 30th turn or so. I'm taking on Baktria, I have the upper hand. Next thing I know all my stacks get attacked, 2 of which were in Baktria's land. Then I gotta end the siege of there capital, but I get attacked as I retreat. Luckily I allied with the right people. They ended up coming to my aid just as my last retreating stack was hit. We won that battle, just barely though.
Oh and Baktria is now besieging one of my cities as well.
AI is so much better than release AI.
I probably should have taken my archer heavy armies west though. They would probably fair better against infantry heavy armies. Not the archer spam of the east.