The main question/comment/idea I have relates to this –
Fact: Mab and Titania aren't the original "Queens" Mab and Titania:
Quote from: 2015 Dragoncon
I was wondering if Mab was the first Winter Queen?
No. Mab was not the first Mab. Mab was originally Winter Lady, and Lea was her Jenny Greenteeth. She was her sidekick and handmaiden. And so when Mab got promoted Lea did too. So she got to be much more powerful and awesome. But that was a while back. When that happened. And the same thing with Titania. The Winter Queens actually died. The last time things got awful in the wizard world. So things are about to get awful in the wizard world again and they're a bit nervous. They're a bit nervous about Dresden. Well, Titania is very nervous about Dresden. Mab is keeping her enemies close.
When you said, at the beginning
I've long embraced the theory that the Winter Court's assumption of Outer Gate duty was concurrent with Mab's ascension.
are you referring to the current Mab or the original?
The current disposition of the various fae royalty comes from a compilation of a number of older Powers into a single pile which was then divided out into the six-part format we currently see. When is it proposed that this happened and most importantly … why? What use a Mother, Queen and Lady for Summer and Winter, with the level of power and responsibility they currently have, before – possibly long before – they ever took over as Guardians? I’m not sure it fits well.
I generally agree it’s likely the Nordics were the previous Guardians, but it’s not necessarily a sure thing. I’ve argued before that if they were, it’s likely that the Jotans were the actual Guardians of the Gates because they have much the same warlike disposition as the current Winter Fae, while Odin and company were more likely in the position Summer now holds, able to get involved with mortals and keeping them safe from the Jotans the way Summer keeps us safe from Winter.
What use would the Nordics have had to have such strong potential contenders for their position as the Fae courts in their current format? It just doesn’t feel right. I think the Fae are older than we’ve been thinking and that, though the current Mab and Titania got their current roles around the time of Hastings, it’s likely that the Fae Courts have been Guardians much longer than that. How long I couldn't say.