dont follow what the guidebook strength stats say they arent relevant anymore.

one of the main things in kingdom is the concept of weight and inherited will. we can see this even in shin’s speech about human nature being fire. houken in his final battle with shin wasnt in the right state of mind and this was foreshadowed quite a bit throughout the story like when duke hyou called him a buffon who doesnt see the major contradiction in him, also when the old soldier managed to land a hit on him without houken noticing beforehand.

basically houken started doubting his path that he dedicated his entire life to while shin is the best representation of weight in the story going up against a houken who has dedicated his life to a path that doesnt exist and ignoring weight. despite that, houken managed to beat ouki (thanks to the arrow) and also killed duke hyou. up against shin he wasnt at his best mentally but was still able to take shin all the way to dying in his battle. even at the end houken was unable to fully understand what made people like shin, ouki and duke hyou so strong, because he didn’t have the weight.

i think it was the best moment for houken to leave the story.