I like the pro/con approach myself, it's just that they are heavily imbalanced in terms of what the player gets from them and what the AI does, as well as how general or niche they are. Some barely impact your game or are highly conditional(having to be a Merc for example to get part of Vlandia's), while others are a massive bonus from beginning to end - Battania being the most egregious outlier here with the move speed in forests.
Some of this is pretty fixable though, I think.Take Vlandia as the current total dud example:
- [Pro] 5% more renown from battles. 15% more income while serving as a mercenary.
- [Pro] 10% production bonus to villages that are bound to castles.
- [Con] Recruiting lords to armies costs 20% more influence.
These are incredibly boring and highly conditional.
What about something like this:
- [Pro] 10% more renown from battles you're outnumbered in. +10 to all skills and 20% lower wages for Mercenary units in your parties.
- [Pro] Allied villages gain hearth when your nearby parties are victorious in battle.
- [Con] Recruiting lords to armies costs 20% more influence.
Bam, now you have perks fitting the same theme but less conditional and that affect your gameplay in some tangible ways. I have incentives to play a Vlandian differently - field more Merc troops, more aggressively go after enemies raiding villages, and take on bigger enemy parties when I can. The more elite Mercenaries at lower wages of course helping with that. And the con makes a little more sense now, as this would be a playstyle favoring spending more time as a smaller party or army.
That's the kind of synergetic and impactful kind of culture bonuses I'd prefer to have, anyway.