Truth be told, when he's in the mountains (an enviroment he knows extremely well) he should be hard to deal with for many. He got beaten by Ousen there but Ousen is just a freak no matter what, and Yotanwa would also handily beat him there because the mountains is also the most familiar enviroment to the Lord of 💀, so rip Ordo.
So I'd think that when the moment to take Ordo down comes, Hara will make it a mountain battle to maximize Ordo's advantage and the Ordo army will also be boosted (he had already started recruiting new mountain lads).
But yeah, ofc the Yan conquest campaign doesn't compare to the bigger ones.