Splitting a name into vowels and consonants sounds like a mechanical operation and is not. English orthography does not divide cleanly into the two categories, and the system has to legislate for the awkward cases, which it does inconsistently between authors.
Y is the standing difficulty. In Yvonne it is doing the work of a consonant; in Mary it is doing the work of a vowel; in Bryan opinions differ. Numerological texts give rules of thumb, usually that Y counts as a vowel when no other vowel is present in the syllable, and the rules of thumb do not agree across the sources this atlas cites for the chart. W raises the same question in names such as Bowen. Since a letter moved from one column to the other changes both the Personality and the Soul Urge, and leaves the Expression alone, the disagreement is not cosmetic.
Behind that sits a deeper mismatch. Vowels and consonants are categories of sound, and the chart applies them to letters. In a language whose spelling has drifted as far from its pronunciation as English has, the two do not line up. A silent letter counts; a sound with no letter does not.
The result is that a Minor Personality is well defined only once someone has ruled on the spelling conventions, and the ruling is editorial. Knowing that is not a reason to discard the reading, but it is the reason two competent practitioners can produce different figures from the same name.