When you think about it, it's funny that every time RBK sets a trap, they all know it's a trap, but they're always like "we'll deal with it, whatever that trap is". It's like they forgot that man is considered the most dangerous man in China, defeated Ouki, set the coalition in motion, is responsible for every delay in Qin's campaign to conquer Zhao, etc...
I understand for Kanki, it was in his nature to try to overturn the tide but fucking Ousen, who doesn't pick battles he can't win, fell for every trap RBk had in store and worse barely tried to do anything at all to counter it. He just let his men do all the work and thinking this arc, what a disappointment of a Great General.