>>724879475
>>724880106
also
>https://forum.paradoxplaza.com/forum/developer-diary/tinto-flavour-47-29th-of-october-2025-content-is-king.1864982/
I don't remember exactly what they said about the tiers but it's basically an internal guide on how much attention a country gets in terms of flavour.
Then there's "generic flavour" as in a tribe has tribe mechanics a republic gets republic mechanics and so on.