The Hoon'Ding intruiges me. It is one of the most powerful beings in the Aurbis. And yet, it only manifests to help the Redguards. I wonder why the Redguards and Redguards alone have a deity to Make Way for them.

Because they are the only people to worship it.

Mortal belief shining through aedracorpsecrystals coelesces into what we call "gods".

See (maybe) Talos and the many faces of Alduin/Aka/Akatosh/ToshRaka/Auriel/etc.

I've been nursing the concept that they aren't.

We see echoes of the Hoon in other cultures. The Shezarrine. The Hortator. It's a tenuous link, but they fulfill the same purpose: in times of great peril, they manifest to lead their people to victory; all others must Make Way.

More the Hortator than the Shezarrine: moon-and-star, sword-and-crown. Backwards men, backwards mer. They even resurfaced in similar manners.

Difference is the Hortator is a political title, just a normal dude elected by the Great Houses as a war-leader. I think you may have confused it with the Nerevarine.

Not a hortator, the Hortator. I prefer that word to Nerevarine principally for aesthetic reasons, though also because the mythic is less about who you are than what you do.

And they need opponents like Dagoth Ur or Tiber Septim (through Richton) to manifest.

The Hortator/Nerevarine fills a role that sounds alike, but the Nerevarine didn't start sword swinging, sure (s)he beat a god at full power, and at least one other god that was weakened later on and an aspect of Hircine, something that no ordinary mortal could ever hope to achieve but I don't see it as having the same power as the HoonDing, so they are alike but not the same. At least not in my opinion.

Do you think the Dragonborn is stronger than the Hoodding, we got godlike shouts like blowing apart walls, causing thunder storms, and all that jazz, what could sword swinging do to rival this?

Split atoms