Are you tired of becoming allies with a faction and 1-10 turns later they attack you? Yup i am too and it's pissing off. I usually play as the Macedon faction and i offer the Greeks an alliance and they accept it(sometimes not) and they attack me next turn either way.
There is a way to make allies with a faction and they will not attack you at all. Gives you their military access, trade rights as well. (As long as you don't attack them, they won't attack you too)
Go to the folder of the RTW game, then go to these next folders: 'data'>'world'>'maps'>'campaign'>'imperial_campaign'. And now go to the descr_strat file. Go to the bottom of the folder.
You can see the core_attitudes and faction_relationships at the bottom for every faction. I play with Macedon so i will show you an example of how to make allies with the Greek cities.
This is Macedon. Make another space for one more in here.
Like this. In that space make it to look like this.
Now that you're done here, go to bellow at faction_relationships and add another faction_relationships bellow the faction you wanna change(for me this time Macedon).
I added faction_relationships macedon, 0 greek_cities here.
Now you can go to the game after this.
I hope this helped, you can do this to every faction you think on playing with. If you do this don't be a traitor and attack your ally