Three parts:
殺人刀 Setsuninto — the sword that kills. The practical scroll: technique, the school's method, what to do.
活人剣 Katsujinken — the sword that gives life. One man's death saves ten thousand. The most politically useful sentence in Japanese martial literature, written by the sword instructor of a government that had just finished conquering the country and intended to keep it.
無刀 Mutō — no-sword. Taking an opponent's weapon, and beyond that a doctrine about not depending on having one.
Musashi has no equivalent of the life-giving sword. Go Rin No Sho has no ethics of the sword at all. It does not say when to kill, and it has no state to serve.
And Munenori's is the book that lost. He had rank, office, a domain, the shōgun's ear, and a school that outlasted him by centuries. Musashi had a cave and a stipend and died within weeks of finishing. In 1650 any informed person would have told you Munenori was the significant figure and Musashi a formidable eccentric with no school worth the name. They would have been right about the facts and wrong about the outcome.