How is Tsar of the Bulgars (Hard) in the Ivalyo Campaign even possible?

i've been trying to beat it over and over again for weeks, and i swear it hasn't been properly playtested. mind you i'm doing it on hard. it just seems almost impossible, you are being SWARMED by mongol and tartar horsemen every 5 seconds, with not enough resources coming in to successfully fight them back. all i can do is build a tonne of castles in my base as that's the only way i can seemingly survive for a while but there's almost no possibility of going offensive, especially because of the resource restrictions in the scenario and the insane kiting micro AI that is just way too good for even a decent player. to top it off, you only get 3 villagers, you cant build an econ and repairing anything is super dangerous because you're constantly being swarmed by the unrelenting AI meaning your villies can die and they're not replaceable. unless you're the viper, this scenario seems nigh unbeatable as it is on hard. i think they really need to scale back the difficulty on this in a patch somehow, it wasn't designed right.