None of those other stats matter much directly in the duel. Wisdom? To a point, yes. And that's what this little trick at the end proved.
However, Ritsu has Weaponry at a higher level, so his use of his weapon should have been superior. Halberd on the other hand is a very bad weapon to use in a forest (heavy blade makes piercing attacks harder, while swinging attacks are almost impossible due to trees around), so there should be little issue to begin with. But of course, next chapter this dudes brother will interrupt the duel and save him, despite the fact that he shouldn't even be alive by now when under such heavy disadvantages.
Meh. This entire battle is just ridiculous thing after ridiculous thing. Somehow the enemies heavy cavalry managed to outrun, on a large detour, the escaping light cavalry, the dude with halberd swings it one-handed to cut several armored people down at once (while on the horse, to boot!), now this. And that's without even bringing up John or whatever is that 'brothers' name...