I recently reread Three Hearts and Three Lions and I'm just not seeing it. Holger didn't have any magical powers.A lot of the early classes were based on very specific archetypes that were around in the late 60s and early 70s- the Paladin was Holger Carlsen in Poul Anderson's Three Hearts and Three Lions.
These, on the other hand, are completely believable. Though the Gygaxian twist had precedent in medieval canon law, and especially in the Song of Roland. (How it makes any sense for clerics of, say, Poseidon, is left as an exercise for the reader.)The Druid was based off of some ideas floating around at the time about early England as envisioned by the Romans and channeled by Denis Sustare. The Cleric was straight-up Van Helsing as seen imagined by Hammer Horror films (with a slight Gygaxian twist of no-edged weapons).
Le sigh.And the Monk? Brian Blume wanted to play Remo Williams.