I kind of see that in the future can there be different sub-civilizations to reflect regional kingdoms throughout different timescales as opposed to having so many separate civilizations like in AoE2, and with different sets of architecture and units/unit designs.
For example Chinese would be the base civilization. While Ming period, Southern Song, Jurchen Jin/Manchu would be the different sub-civilization iterations of this base civilization
For Mongols, there could be different types too, for instance Khitans, Khalkha, Oirats, Buryats or Xianbei. As well as a separate Kipchak-Tatar-Cuman or Bulghar-Avar-Hunnic civilization representing Turkic cultures of the steppe like in the AoE2 definitive edition.
Europe, Middle East, Africa and Southeast Asia there is so much potential too.
Isn’t this already in the game with how age-up works? Particularly for China which can build towards different dynasties, but beyond that all Civs get to choose a landmark each age-up that apply a variation.
I also believe cultures like Iranic/Central Asian, Baltic, Finnic, Tibetan-like cultures like Tibetans, Tanguts and Dali… and also tribal Southern Chinese, and Viet cultures could be better specifically flushed out.
And also as opposed to the Indian-influenced civilizations on the Southeast Asian mainland like the central Thais, Burmese and Khmer or the seafaring, island Austronesian cultures
Because sometimes there are large gray areas that need to be addressed that can complicate things in terms of visual perception
Recent findings are proving that most of the Hunnic (The Huns) skeletons and their genetics are matching with the Mongol ones. in 2018, a group of expeditionists and archeologists found a tomb of the Huns exactly the same as the ones in Hungary. They collected the skeleton and bones and matched them with the ones in Hungary. More than 80% matched the Mongol DNA and the shape of the skeleton and bones etc. The religion the Huns believed is “Tengri” the eternal blue sky which is exactly the same as the Mongols. Even the “Hun” originally a Mongolian word for human you know the band “The Hu”. Turkic people don’t have the words such as “Tengri”, “Hun” in their main language. They (the Huns or Hunnu, in Chinese Xiongnu) even came from central Asia xD. But of course, what I wanted to say is that it was a huge confederation of nomadic tribes that included various people from many different regions including Mongols, Turks, Avars, Jurchens, etc. After the defeat against Tang Dynasty, it divided into many small tribes and formed Mongol tribes, Tatar tribes, etc.
The Hunnu or Xiongnu is not defeated by Tang dynasty, it was defeated by Han dynasty, which was much earlier in history. The Gok Turk empire was defeated by Tang dynasty and divided into small tribes, including mongols and Khitay etc.
In the Tang Dynasty, many foreigners held important positions in the Empire. At that time, two Central Asians, Anlushan and ShiSiming, served as military generals in the Tang Dynasty. They held important military power and launched the famous Anshi rebellion out of self-interest, which greatly damaged the vitality of the Tang Dynasty. They even transferred the troops stationed in Central Asia back to pacify the rebellion. Because of this rebellion, the Chinese have since been less trusting of foreigners or foreign officials.