There's actually a Horde Grimtotem Faction, lead by Jevan "Stormsong" Grimtotem, which stands as one of Baine's MOST trusted advisors http://wowpedia.org/Jevan_Grimtotem there's a significant population of Horde Grimtotem, it's like a fraction of the whole of the Grimtotem tribe, but there is a significant presence since they're their own sub-faction within a faction.
Also, San'layn as a sub-race... The question seems redundant since they're already added in your list of sub-races under their proper name Darkfallen. Anyways, there are currently 2 surviving Blood Princes, probably with a following of a few supporters, nothing in the form of an army, more like a tiny warband enough to defend themselves, and then a TCG Darkfallen named Blood Lord Vorath is a survivor too.
And as said, the Azotha doesn't exist in lore... The forsaken part of that quest of looking at your ancestors with Lorewalker Cho is pretty much proof, there's Undead first, then humans, then vrykul, nothing between humans and vrykul. So yeah, Azotha doesn't exist in lore.