We had a discussion among staff once when the rank changes happened (i think that was before you joined) and I brought up a few "lore-accurate" rank namings:
REFERENCE: Todays ranks:
Oathbreaker
Adventurer
Guide
Artist
Designer
Enforcer
Head Designer & Head Enforcer
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LORE VARIANTS:
Oathbreaker: Thats okay and I wouldnt change it as this one is clearly comprehensible
Adventurer: This is awesome like that, supported by the often heard "I'm going on an adventure!" quote aswell as one of the main expected actions of people with that rank.
Ranger: Rangers if the North, people who know their way around the map.
Artist: I dont know if this term ever appears in Tolkiens writing, but one speaks often of "Elvish arts" and a person doing those art is an Artist.
Jewelsmith: In Tolkiens writings Arts seem to take in a fairly small importance and thus its hard to find a race-neutral term that is in the lore and covers all activities of Build Mods. . .
Guard (Ex-Enforcer/Bounder), reference to the Guards of the Citadel, the elite-soldiers of Gondor that protect MT's 7th level
Vala
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A bit more bold list using the races of Middle-Earth:
Orc, or with a nice matching double meaning: Troll
Hobbit
Dúnadan (pl. Dúnedain)
Dwarf
Elf
Istar (pl. Istari)
Vala (pl. Valar)
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Or:
Oathbreaker
Adventurer
Ranger
Artist
Maia (pl. Maiar)
Istar (pl. Istari)
Vala (pl. Valar)
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However the reason why in the end we sticked to non-lore ranks was, as you said, to respect people that arent so steadfast in the lore and thus having rank names that are self-explaining.