[HoneyBadger]

I have a partial solution-to follow what I think Gandalf has in mind.

Why not, with nation creation, and hard coded into the game, establish a diplomatic reaction table that- independent of what a player does-keeps track of how the AI playing one nation, reacts to another nation?

If you blood-harvest or summon undead or maenads or demons, indeps should attack you, because you'd be viewed as a threat, and AI nations should have a tendancy to ally against you.

If you have a large, disciplined standing army, that should make indeps wary of you, and build up their defenses, but if you give them gifts and don't step on their feet, they should look favorably on you, and be willing to help you, let down their guard, or even open trade relations and alliance options. It would also furth distinctify nations from one another.