Comments - TheXanian

Here's my idea about China and Japan.

Chinese

Infantry and gunpowder civilization

Unique Units

Paper Armor Militia: a fast militia units armed with paper armor and bamboo spear, good at countering skirmishers

Zhanmadao: a heavy infantry armed with a horse-cleaver polearm, good against cavalry.

Kedigong: a heavy crossbowman armed with an arbalest, also good against cavalry

Unique Tech

Landmine: Petards would gain extra bonus against cavalry

Military Manual: Halberdiers, Zhanmadao, and Paper Armor Militia +1 attack

Poison Powder: Kedigong, Scorpion, and Hand Cannoneer +1 attack

Japanese

Infantry and archer civilization

Unique Units

Samurai: a heavy infantry unit, good at countering other infantry

Yumi Archer: a heavy bowman, good at countering infantry and skirmishers

Yari Pikeman: a heavy pikeman, good at countering cavalry

Unique Tech

Kendo: Swordsman and Knight +1 attack

Bushido: Samurai and Yari Pikeman +1 attack and moves faster

Kyudo: Crossbowman and Yumi Archer +1 attack +1 range

Nice job with the Chinese castle age building set, I really like it. The original Asian building set was indeed based on the Japanese style, which looked quite awkward when playing as China, Korea, or Mongolia.

Maybe you should also add some new unique units to the Asian civilizations. Let's take China for example (since I'm most familiar with Chinese history). Chu Ko Nu, as far as I'm aware, was more of a civilian weapon, not really used on the battlefield. Thus I think it's not a suitable unique unit for the Chinese.

Here's what I have in mind about the possible new unique units for the Chinese in the castle age:

Paper Armor Militia: A rather cheap and fast militia unit wearing paper armor and wielding a bamboo spear, good against skirmishers and archers, but bad against cavalry and infantry.

Spraying Tube: Another cheap and fast militia unit armed with a spraying tube (it's basically a bamboo firelance) that can spray fire like a fire ship, good against siege units, buildings, and villagers, but bad against skirmishers, archers, and cavalry.

Kedigong: A medieval Chinese crossbowman armed with a arbalest, good against cavalry, but bad against skirmishers.

Hope my ideas would work with your mod.