Any documentation (other than the Anuad and Monomyth) or speculation on this particular schism? What I find interesting is that by Merrish convention the Yoku would be classified as "Wanderers" yet they, and by extension the Redguards, hold a staunchly Anuic set of beliefs. Perhaps they were the first (or last) people that left Tamriel to wander and it's because of this that they retain their Anuic beliefs? Any theories out there?

It's certainly an interesting point, but there isn't a whole lot on it. Being a "wanderer" and anti-Lorkhanic are not exclusive, evidently, but Redguards don't really match with the "stasis" interpretation of Anu. Arguably the most important spirit to their race is one of "Making Way", change and progress.

I guess that to them Nirn is inherently unsatisfying, not - as to mer - a fragile reminder of what was, but rather pale in comparison to what could be. The crux of the Satakal myth is that we are trapped on this ball of skins, and Truth/immortality is not here, it is on the Far Shores, which cannot be reached by direct means. It's reflected in their tradition of explorers, voyagers and invaders. Like Aldmeris, the true Yokuda of their hearts may or may not have ever existed but it is rather something to be reached for, outside of this world.

While I don't have anything to contribute right now, I'd recommend paying some attention to the details in http://www.imperial-library.info/content/lord-vivecs-sword-meeting-cyrus-restless, as it's set on wrecked Yokuda and I know MK has thoughts about what the first arrival of Ra Gada on Tamriel's shores entails, how the first Redguards encounter people who are humans as they are, not mer, and how war erupts.