Well, we had many different nations in 1700-1900 (approx. time line of the game) but plenty of cultures were unique without being independent national states. It is a question how accurate you want this mode and how reasonable it would be to prefer quantity over quality.
But lets discuss a concept i would like to suggest. First, sorry for my English - some words i want to use are very specific and i am afraid i cant use them always 100% correctly.
Well, i was thinking about something like Vassal cultures - cultures that were not fully independent, and that relied on their "superior culture" (f.e. Czech/Slovak/Austria etc. during Austria-Hungary era). These "not fully independent cultures" (i am sure there is some nice word for that
) could be used as brand new group.
They would be very different from what we have now:
- They will have unique currency - Loyalty. It could be gained trough f.e. sending resources to superior nation (trough f.e. some trading company, market building etc.), sharing religion with the nation, killing enemies etc.. Loyalty will be used for almost everything - you will be defined by your "ruler" so Loyalty will be needed for technologies, age advancement, unit upgrades etc.
- Thanks to Loyalty, common resources (food, wood, coins) wont be that much important. Food will be needed for buying settlers, wood will be needed only for basic buildings. Loyalty will be the most important resource and you will need to adapt to it. Without serving to your master, you wont get any benefits and your culture wont grow.
You will be able to gain resources ONLY from natural sources like woods, animals, berry bushes, silver/gold deposits etc. Buildings like mills or plantation will deliver products to home country, giving you Loyalty in return.
- With loyalty and power of your Home country behind your backs, these minor cultures will have very strong decks/Home City. Instead of getting few units from one shipment, you will get dozens of units as a reward for your Loyalty (yes, you will have to pay for these shipments). Some units could be sent infinite times, which will provide contant source of military power from Home city.
- You will still be able to buy units from barracks/stables etc. - there will be 2 types of units. 1st - units used by your king/master/ruler (same you could send through shipments) that could be bought for Loyalty and 2nd - your specific units (Polish Husars, Czech War Wagons etc.) that will be very strong, but you will buy them with regular resources (they will be rare for reason i wrote above).
Dunno, it may sound weird but i honestly think some minor cultures that are fully dependant on other culture/state (with powerful cards in deck but limited own potential) could bring some new elements to the game (mainly through Loaylty toward the ruler)... along with new cultures that exist now, but they were part of bigger nations/countires/culture before (despite of having unique cultural elements, units, etc.)