yes look the trouble with trying to examine the weirdness of the Dungeons & Dragons Cleric solely through the lens of "E. Gary 'Genocide Enthusiast' Gygax was a specifically-American-Christian fundie" is that — although he was and it's definitely in the mix — you start running into the problem that, although he lied about it a lot for commons-enclosure purposes, Gygax was a pedestrian, uncreative shit, many of whose original contributions have fallen into obscurity because they're obviously bad; early D&D is promiscuously syncretic. Some of the ways it's weird are because it's not what he'd have written himself, if he'd had enough fucking ability to write stuff himself, with the cracks crudely papered over.
During his tenure, D&D never stopped its constant process of accretion and revision, and despite Gygax's repeated attempts to order his packrat mess, he refused to ever throw anything away, only ever attempt to build larger, grander, more elaborate, Nerd Wiki Completionism Impulse-style frameworks to enclose everything so far, that would explain away any apparent inconsistencies as mere epicycles. (The entire Planescape setting, authored by other hands, is a more-competent fulfilment of that post-hoc systematisation!)
(That, too, breaks down later in the game's history; under WotC's tenure everything bends inexorably in the direction of ouroboran corporate autocoprophagy, and the diktat to never write "mermaid" if you can invent something like "anthraquatikoi", because the powers that be will only let you tack a ™ onto, ergo sue people over, one of those. I hate Monster Manuals, and the 4e is the one I hate most.)