Yeah. Atomic mass: Makes no sense, argon is larger than carbon. Frequency: Makes no sense, argon is least frequent of the three and hydrogen is everywhere, so carbon would be in-between rather than the flagship.

Letters of the alphabet: Also makes no sense. There was a theory that Argon = A, that there was an unreleased B model (Bismuth or Barium or something), Carbon = C, etc. (Similar to Intel's MMORPG-inspired Alchemist --> Battlemage --> Celestial...) Hydrogen broke this notion.

It's just completely incoherent.

Now written out like this, I can see a D = Deuterium, which is mass 2 or heavy hydrogen, but somewhere along along the line it was lost in translation.

Molecular mass tracks.