A lot of neat theories. Yea, I say the mutilated are the best thing Bakker has going forward, intrigue wise.
I like the idea that he was an inside man, or the first to surrender to Mek atop Ishual, while Mek waxed poetically about the Ark, Consult and the IF. What a scene that would've been !
Though, I thoroughly believe the mutilated to be Shae.