Even if we remove Tou the Duke can't beat Ouki simply because he's weaker than him and that's really where he meets his limit.
He's the upset guy up against Tactician/Strategy gods like Gokei or even Riboku.
I can see the arguments but I'm not sure of Hara would make it clear for any other of the previous Qin 6 that they were directly inferior to Ouki as he did with the Duke, after all Ouki said that the Duke would give him a run for his money implying that he would surely win.
Even the Duke was like tf you doing bro.
SBS yes but Kanki debatable.
I say it all the time but Karin isn't that big for show and she also kicked a commander with a basic kick for reason. Hara wanted to show off that brute strength.
If she can take on Zenou she's taking away the fear of Kanki's greatest weapon and even RBK was shook by that.
@Elder Lee Hung
Do you think the Duke can slay Zenou and still have enough strength left to win the war against Kanki ?