I actually think I'm going to vote for Houken in this matchup lol, mainly because I don't think the Kan Ki Army really has a real answer to him as a warrior. I don't think anyone should underestimate the sheer ferocity of Houken's martial strength.
On top of all the stuff Hou Ken is typically known for (fighting on par with Ou Ki, thrashing Duke Hyou, low-diffing Geki Shin, etc). this is the same dude that was tearing his way through Mountain Warriors with ease and
with a broken arm:
On top of this, Gekishin's personal cavalry, which are actually Quan Rong troops who are basically equal to Mountain Tribe soldiers:
And Houken thrashed the absolute mess out of these men:
Hou Ken's raw martial skill is so extreme that even dozens of men attacking him all at once means absolutely nothing:
And I just don't think Kan Ki's methods of warfare will have any effect on Houken himself. Nobody in Kanki's army bar Zenou is pushing Houken to mid diff in a fight, and even Zenou is just a brute whom Houken will easily outskill and slay pretty quickly. Unless Kanki shows himself to be a damn artist with the sword, then he truly has no ability to slay Houken here. Absolutely none.
And this is even underestimating Houken's own subordinate Generals and assuming that they won't be able to deal with Kanki's subordinates when really there's not much yet that supports that notion.
Two of Kanki's most capable subordinates, Rai Do and Koku'Ou aren't even Generals, Rai Do is a 4,000 Man Commander while Koku'Ou is a 5,000 Man Commander, while Hou Ken has
actual Generals by his side (and capable ones too like Kou Son Ryuu and Chou Sou).
So really Kanki's subordinates debatably don't even win their matchups against Houken's if you want to take statements about their ranks seriously.
But even if Kanki's subordinates, somehow using their unorthodox tactics, manage to outplay Houken's, there is still the problem of Houken himself who again, Kanki's army really has no way of actually dealing with, unlike Yo Tan Wa who could actually overwhelm him with brute force and a strong ass army.
Houken isn't stupid, he isn't going to try and slay all 100,000 of Kanki's bandits by himself, he'll spend most of the battle hiding until he spots the perfect opportunity to bust in and slay Kanki's commanders and eventually Kanki himself, without too much resistance tbh. And the Kanki army has no answer to this other than to call repeated retreats in an attempt to slowly widdle down Houken's numbers, and I'm sorry but I think Chou Sou and Fuu Ki would not allow this to happen so easily.
The Hou Ken Army wins this, around a mid/high diff.