I think the bug with the Bunshido not attacking is due to her having an Iatowashi Sheathed and Stool equipped in her hands by default. The Iatowashi Sheathed can't be used without an empty hand. I unequipped the Stool and she used Sheathe Buff (or, uh, "Seathe buff") and Iatojutsu as a follower.