chu ko nu (zhuge nu) was invented around 200AD(cant remember) by zhuge liang
this guy is regarded as the wisest man in chinese history,
he is a master inventer,invented many machinary such as repeating crossbow, Ox horse??(sor of automatic wheelbarrow thingy), hot air baloon.
he is a master tactician, the famouse battle is "battle of chibi"(battle of red cliff)
winning over near 1 million army with little of 50 thousand troop.
under his command, their side almost have no lost battle
he is the master of geography and astrology, he predicts weather that helped him to win the battle of chibi.
chu ko nu is like the machine gun of the ancient age, same rule as today, a submachine gun loses fire power, range, and accuracy over a regular rifle, but allows rapid fire.
if u have to go to war, and u have a choice to pick a bolt action rifle, or a submachine gun, u probably will the submachine gun.
other possible chinese UU can be the "fire lancer"(borrowed from rise of nation) that replaces the musketeers, instead of firing round bullets, they fire rockets of fireworks, much more damage and range.
another possible chinese UU can be the "wuxia"
. similar to knigh errant in the western world and sumurai in japan. what is wuxia? crouching tiger and hiden dragon is all about wuxia.
it is very unique to chinese culture, thus, western world have little knowledge about it,