Hmm. This is a tough one.

I'm going to scratch Dunmer Ordinator off the list. I have a Dunmer Ordinator character myself, and I made her a Templar. I think that a Templar suits that kind of holy warrior a lot better than a Sorcerer would, considering that the entire class is filled with deity-related overtones (and Almalexia's persistent particle effects look more like the Templar's particle effects than any other class).

Bosmer ranger strikes me more as a Nightblade than a Sorcerer, since "ranger" generally implies "sneaky."

That leaves Orc Berserker and Redguard Sword-Singer. The Orc could be interesting. You could make it some sort of metaphorical thing, like the storm they carry with them sort of being a manifestation of their fury in combat. But that might strike you as cheesy.

I think the Sword-Saint is probably the most logical choice. Sword-Singing is obviously a pretty complex form of magic, so it makes sense for someone trying to learn it to be well-versed in magic in general to try to better understand it.

So I'll have to go with Sword-Saint here.