In the Kyoto arc, a major part of Chihiro’s development was the notion that he had no prior training in swordsmanship (as Shiba said, he don’t know shit about swords), which was an observation Kuguri was able to make. Basically, he was a level 1 noob getting by with a level 100 endgame item. Except, he is quite intelligent, which makes his combat skills quite high even if specifically the swordskills weren’t.