Difficulty with "Into China" mission, AoK campaign

I was just wondering how you guys managed to beat the Into China mission in the Genghis Khan campaign line. It's the one where the Jin Dynasty (on the other side of the map) starts building a wonder soon after hitting imperial. I'm playing on standard difficulty and this seems 1000x harder than the other missions I did on moderate difficulty. I'm not even *getting* to Jin in time. When I use cheats to spy and scout around his base, he spams cavaliers at a much quicker rate than I possibly could. I'm not great at the game, but this is on standard... I can plan out my entire strategy, where I build my TCs, how to best use my 75 cap space, and still not even get close. I see that ideally, you can wall some trebs behind his wall and poke his wonder from there, but with his cav spam, I don't see how getting the trebs there would be so simple

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The most detailed guide I found says that Jin only uses 1 worker to build the wonder, but he uses lots in my games. I guess an update made it more difficult?