Varieties of Faith mentions that since Herma-Mora is Mephala's brother, he is related to the origins of the Morag Tong. Additionally, Hermaeus Mora translates to the Old Man of the Forest, while Morag Tong translates to Forester's Guild. Also, the Book Sithis appears to be Tribunal Temple stuff, judging by quoting from the Sermons and mention of the Sharmat, and it has "HERMA MORA" in an ehlnofex incantation. Additionally, the 36 lessons have a bit which says "The coming forth and the driving away brings all things around. What I shall say next is unpleasant to record: HERMA-MORA-ALTADOON! AE ALTADOON!", but since it was in quotation marks and Ysmir was driven mad by the shout-helm in the previous sentence, I take it as his insane ramblings, and it would make sense for a crazy Nord to mention the villain of the Ysgramor tales, which were likely pretty popular.

So Hermaeus Mora has a role in Dunmer culture. But to what end? He isn't of the Good Daedra or House of Troubles, yet he seems to have more of a role in their beliefs than all the other left out Daedra.

He's everywhere. His pandextrous eyes worm their way into all the tiniest cracks of history, and so observe everything as it always is. It's hardly surprising that the Dunmer noticed a few of them peering out of the shadows here and there.

Woodland Man: demon of poetic justice and derelict, or ancestral, wisdom. He is the cadence of clever men's prayers, liars who steal, and beggars who murder.

The Tong only exists, because areas of the web appear to need a villain's daggered fist. They're as fictitious as the DB of Morrowind, Cyrodiil and Skyrim.