Another thing to consider is that firecarts are essentially the 'German mortar' infantry of the Koreans. They are expensive area damage units that your opponent can't deploy until mid-game. You have to attack a Korean player (just as you have to attack a German player) fairly early and you have to damage his economy while you continue to build your own.
It is more difficult in Medieval to figure out the best attack vs. Korea (unless you're England and can see them) because Korea can build spear and/or sword infantry, and sometime will build Horse Archer - so as China you don't know whether to attack with Mongol Horsemen, Song Guardsmen or Song Spearmen at the outset - but that keeps it interesting.
China is Medieval's "Russia" (lot's of cheap early units) and Korea is Medieval's "Germany" (few, high quality units).
It's true, Elephants and Sorcerors own later in the game for China vs. anyone, though. [This message has been edited by chonaman (edited 12-17-2004 @ 07:14 PM).]