There used to be speculation that Zurin was even an elf of some kind originally.
And also Greybeards' stories. Maybe Hjalti was in fact from Atmora? I don't like the idea that the only Atmoran element in Talos was half-dead Wulfharth.
Could Talos of Atmora be in another reality (where Vivec was god), which fused with Hjalti's by Dragon Break?
It greatly reminds me Vehk-and-Vehk situation.