So in RTW we are allowed a grand total of just 7 cultures, and on top of that we are allowed 3 working religion slots.
Our cultures:
Roman - Rome
Greek - Greek Cities, Macedon, Seleucid, Hellenic Kingdoms
Eastern - Parthia, Pontus, Armenia, Nabataea
Carthaginian - Carthage, Numidia
Egyptian - Egypt
Barbarian - Gauls, Celtic Tribes, Germans, Dacians, Iberians, Illyrians
Nomad - Sarmatia, Saka
Our religions (culture in-game):
Western Civilized
Eastern Civilized
Barbarian
Okay so religions are not assigned to factions, but instead to characters, buildings, and regions. So Rome can have a barbarian region, but have a Western Civilized Governor, which would mean unrest. We can add more religions or 'cultures' to be more diverse but they do not have the same hard coded effects. For them to be effective, they'd need to have traits I believe.
So if we want to add more we can, but for now the 3 we have are pretty good.
Now for the 7 cultures, I have a few ideas before we move on from them.
1. Change Carthage to Eastern, keep Numidia as Carthaginian which would be changed to African. There are Numidian Portraits available, and the African culture can represent Numidia, Mauretania, Gaetulia, Garamantia, Libya, and Ethiopia.
2. Keep Carthage as Carthaginian, but add Iberia to be Carthaginian. Make Egypt Greek, and turn Egyptian to African. Then make Numidia African for same concept.
3. (Best Proposal imho) Make Egypt Greek, and Illyria Greek. Make Carthage Eastern. Have Numidia be African. Make Gauls & Celtic Tribes, Celtic. Make Parthia nomad. Would end up looking like:
Roman - Rome
Nomad - Sarmatia, Saka, Parthia
Greek - Greek Cities, Seleucid, Macedon, Egypt, Hellenic Kingdoms, Illyria
Eastern - Carthage, Pontus, Armenia, Nabataea
African - Numidia
Celtic - Celtic Tribes, Gauls
Barbarian - Dacia, Iberia, Germania
Now Illyria can still be barbarian, Dacia could be Celtic. Parthia can still be eastern. None of those changes really change anything. But having an African culture and splitting up the Barbarians does change it. This would mean that Carthage will have a culture penalty in Africa dealing with the Numidians, and it means that the Gauls and Celts will be surrounded by a different culture making a clash with Germans and Iberians inevitable. This adds flavor to the game as we can make the 'Dislikes Celts' trait etc.
The only thing I dislike, is the fact that I just feel like Iberia and Illyria are semi-civilized and they just don't fit anywhere.
If anyone opposes let me know, otherwise I think we should give it a shot.