I feel like with the Absolute Swordsman User, they'd even be capable of taking on Yoriichi. It wouldn't be a stalemate like I thought about considering Yoriichi fills some of the application of Absolute Swordsmanship but not entirely.
One notable application that the User would have over Yoriichi is Absolute Slicing. Yoriichi hasn't demonstrated a single feat to be considered even near this so ultimately the Absolute Swordsman would win at the end of the day.