Well, the Korean war really starts to drain our capacity...
I checked back to the 1000 BC save. There were a bunch of barbarians to clear out OR the tax slider could have gotten set to positive and just let them run into a border city. But, it's also been a while since they've been gone. Mongolia knows Mathematics in 1000 BC (and probably earlier?).
Between 350 BC and 150 BC choxorn was the first player to put catapults. And only two (which is better than nothing!). This isn't the Mesopotomia scenario, as fun as that is, where catapults aren't available until somewhat late. I'm not an expert at Always War or early war games with infantry-type units only (and I tend to use a bit modified of AW rules also). But, I think remember LKendter saying that catapults early help a fair bit to minimize losses in AW games. In my Always War experiments I remember the 2nd or 3rd time when I started building catapults earlier rather than later, things seemed to go better. And when every offensive unit has maximum speed of one, combined arms always can keep up, unlike how a cavalry charge before artillery proper can easily outrun projectile weaponry.
Try to take Ch'ongfu. But probably that'll be possible only after retreating for now, fend off some more Korean units while minimizing own losses and refilling our ranks? If you failed with 12 archers, I should probably take 20?!
I haven't done the calculations, but no doubt that would project to a fair number of archer losses. Again, all three Korean border cities are on a hill. So, my suggestion is to wait until you have a stack of catapults or an archer army (protected by a spear or two) before even thinking about attacking Korean border towns.
Thing is though, Korea does have some desert (and a fair number of hills too), and I think they have the most territory on the map (check the power ranking and especially the score if you want to confirm/argue this). They already have Invention, and thus will soon have Gunpowder. So, I won't feel surprised if they get muskets soon.
The Great Library is still available, and everyone but the Byzantines have an extra luxury or resource for disconnect-reconnect strategies to get technology and/or gold. It also looks like Mongolia's trading reputation is still intact, since after paying for peace with Korea, I could pay them 1 gpt for 16 gold (and Henry would take 1 gpt for 7 gold).
Also, longbows cost the human player 40 shields. That's (.7 * 40) = 28 shields for a demigod AI. So, a human player building archers can build archers more quickly than a demigod AI building longbows. But, yea, you probably want some pikes, muskets, *or* a spear army to protect against longbows attack. But also, their defense value is 1, the same as an archer. So, I don't think them getting longbows is too concerning all things consider. Them marching muskets into your territory without enough firepower though, I would feel as concerning though.
Anyways, it's good to see this active and thanks for all the reading and saves people! Hopefully, I haven't been too harsh with my comments.