I don't understand the relevance of this "enantiomorph" (not sure how you came to that term, so I'll just call it a trinity) to classic DnD. By the time Arena had come out, DnD had already released its second edition five years prior, which split classes into four categories, Warrior, Wizard, Priest, and Rogue, and Rogue didn't necessarily constitute "Thief" per se, because Bard also fell under the rogue category, which is a caster. I doubt this trinity is intentionally present in the TES universe. In Arena, all you did was choose a class from the entire list. In Daggerfall you chose a class or made your class, and if you made your own, you only chose primary skills, major skills, and minor skills. It wasn't until Morrowind the concept of Combat, Magic, and Stealth was introduced during character creation, and it was just as quickly removed in Oblivion. As far as birth signs, you're choosing three out the thirteen birthsigns they offer (these birthsigns weren't even available until Morrowind). Is there even somewhere that suggests the Mage, Warrior, and Thief are the "prime" constellations?
Pegging the archetypes was the point. I mean, paladin is splitting hairs, and techno mage is still a mage.
But how does warrior-poet translate into Thief?
As far as modern Aldmer go, what about the Orcs?
That just leaves Talos. I don't wholly understand the concept of Talos. I can't find any significant lore on how Talos came to be. All lore I've found seems to simply suggest that Talos is Tiber Septim's birth name, and Ysmir (Wulfharth) is his Nordic name. Even if this suggested trinity does exist within Talos, that wouldn't seem like a lot to base the trinity itself off of. It takes two points to make a line.
EDIT: Yikes, I need to wake up first before I post this kind of stuff. They didn't remove Combat, Magic, Stealth from Oblivon. ^^