This rhyme gives you the first letters of the twelve cranial nerves in order. There are other rhymes that work, take your pick. You must learn the names, numbers (always use Roman numerals), and functions. There is no need to learn a rhyme for whether they are motor or sensory. Knowing their functions will tell you if they are motor or sensory. And the fact is that, while some are sensory only, all of the motor nerves have sensory proprioceptive fibers, despite the rhyme and the table in Marieb.