Of course they work!
They're just at a disadvantage, but they
can win.
Amrelath: plays as a Sorcerer with massive saves and a fondness for punching people

And he has Ancestral Awakening and Wings of Cover, that's pretty good.
Glyra: borrows a few spells from Daenerys, uses alchemical items (hide in smoke, entangle people, etc)
Moonsong: illusions to hide of she wins initiative, then probably lose unless her hideous laughter works somehow. Sucks to be her, but her pride and good saves means that it makes sense for her to get this far!
Mia: yeah, she'll probably lose fast. Sucks to be her. But she's powerful enough to get this far (assuming most entrants were scrubs) so it makes sense for her to lose here.
EDIT: You know who's really screwed here? That level 5 Scholarum Sorcerer. He doesn't even have level 3 spells! What a madman!