I don't think Minphilia is one, after all

SPOILER

She was just a kid back in V.1 during the echo stories, yet the archons were already at least around 20-25.
Besides she comes from Ala Mhigo, not Sharlayan.

SPOILER OFF

And about the Roegadyn they mention in the other thread, Greinfarr, he isn't either, He's just the son of one of the syndicate member like the rest of Niel's group, besides, Thancred would have recognized him at the very beginning of V.1 if he was an archon too.