This was a nonsense fight if you think about it. Aoshi was lamenting how the war skipped his own battlefield, robbing him of his chances to shine, yet here he is supposedly dominating a person called the strongest, who lived through all the battles. However, looking at this particular fight, Kenshin didn't even use his fancy techniques. He ought to have been able to finish Aoshi quickly with them, but he must have thought the inexperienced Aoshi doesn't deserve them. Too bad Kenshin, by voluntarily fighting with one hand tied behind his back, accumulated all those wounds.