First, Chinese players will no longer complain that Chinese is too weak, as the Song Dynasty’s cavalry was inherently not powerful enough.
Second, would explain why there are multiple Chinese-speaking civs, and even allow for the possibility of developing more dynasty DLCs in the future, similar to the variant civilizations in Age of Empires IV.
3K is a mistake that was used to bait Chinese audiances into parting with their money, in exchange for a low-quality product that does not fit in the game.