So there are actually two things I wanted to discuss here, but the one didn't seem to warrant its own thread given that it ties somewhat directly into the main topic. Since this whole idea began with that first question, I'll start with it:
Can we assume the Mutilated totally underestimated Cnaiur, not just regarding his "loyalty to the cause" but furthermore in terms of just how clever, and how crazy the Scylvendi really was? For one, I think we can rule out a face-to-face meeting having occurred between him and Consult Dunyain. Indeed, whatever 'deal' Cnaiur had with the Consult likely preceded the Dunyain usurpation, and was (one must assume) handled almost entirely through Not-Serwe, maybe a meeting with the Synthese here and there. In any case, unless we presume that the Mutilated actually planned for Cnaiur to go AWOL at the last moment (which seems very unlikely -- the only possible reason I can see is as a way to get Cnaiur out of the picture, since he's crazy, but if the Mutilated were aware of that then there are far easier ways of dispatching him).
So that leaves Meonghus, now the King-of-Tribes, and as far as I can tell...Emperor of the Three-Seas?
From what I can tell, the PR spun by Kellhus was that Moe was totally legitimate, which also makes him next in line for the throne. We might assume that, were Kayutas to survive and have means, he could potentially pusue and probably attain rulership of the Three Seas. If he survives. If he even wants it. The same can be said of Serwa.
Yes, Momemn is in ruins, and in general the Three Seas are depleted of martial resourses. But Moenghus has the entire Scylvendi army, and all their Chorae -- so not only does he have the right to claim the Empire, he has the means to take it.
This seems like it could potentially be a rather interesting narrative path. While we've been battered over the head with the idea that the Empire was just a stepping stone, this was only from the perspective of Kellhus and his goals. With the Fanim threat already deal with, this leaves the entirety of the Three Seas open for the taking, and I'm not sure Moenghus would view what remains of the Empire as being without value, especially since the main thing the Empire lacks is a fresh, trained, and armed batch of soldiers -- the one thing Moenghus already has (not to mention things like Chorae, and for all we know, the Heron Spear...the Scylvendi were the last known possessors of it).
I can't say I'm sold on this whole idea, although the fact that it hasn't occurred to me personally until recently is intriguing, and the possibility definitely lends a better sense of direction to how events may unfold on the human geopolitical side of things (which, as we know from the Last Apocalypse, hardly came to a halt once the No-God walked).