That dastardly AI is all mechanical scheming, expect to be burnt. In MTW and probably STW too the ai will gang up on you if you are strong, never allying to you, even if you are rediculously overpowering. Say they have 1 mere backwater province and you own 2/3rds of the map they still will refuse an alliance. If they didn't perhaps they would constantly try to be allies with you near the end of the game making it less enjoyable.