Some cultures and or culture groups in my opinion should be renamed or further altered to add more accuracy. Here is some of my suggestions and why they should be done here:

1- Rename Coptic to Egyptian/Aegyptian and rename Arab Egyptian to Mirsi.
-Why? Arab Egyptians never referred to themselves as Egyptian but as Mirsi.
The word is rooted to have meant civilization but in recent times became the Arabic word for Egyptian. Additionally the word Egyptian comes from Greek and is what Coptic peoples referred to themselves as. Coptic historically was used mainly by Latin speakers to refer to Christian Egyptians making it not as good of a word to refer to an ethnic people / culture when religion in CK3 is separate from culture / ethnicity.

2- Rename Eastern Roman to Hellenic and move Macedonian and Trojan into the group.
-Why? Their is little ethnic and religious changes from peak Hellene period to pre-Arab conquests. Makes more sense for them to be in one group.

3- Rename Briton to Brythonic
-Why? Briton refers to anyone ethnically from England and includes Anglo-Saxons to modern Americans. Brythonic refers only to ancient Britons making it better usage for the culture.

4- Rename the Ancient Egyptian culture to kemet and move it into the East African culture group.
-Why? Kemet was the offical term A.E. used to refer to themselves. Additionally they had strong ties to other local cultures so it makes sense to move the culture into the East African group.

5- Rework Vlach culture.
-Why? The term Vlach is a Latin term that refers to the East Romance peoples. It is not limited to Romanian and represents multiple in game cultures some of which are just Greek that speak a Vlach language. Additionally I think adding an dead Dacian culture would do some good but might be out of mods scope.


Lastly these are just my suggestions based on my general knowledge from light studies.
I could be wrong on some things which I will cede. Personally I think doing what I listed above will improve the Mod greatly.