The way the TW AI works seems to work is with each faction having a 'like' counter to every other faction. At the game start they are initiated at zero. That's why you can declare peace so easily at the begining of the game. All diplomatic patterns for the game will probably be made in the first 20 or so years. After that everything is locked in pretty much. If you expand slowly, reasonable, and are quick to make alliances, you will probably have atleast some friends.

I've even had them gift me a few hundred mnai. I've also borrowed 10000 mnai from the Romans once.