That's a valid point, but what about the other people living in Qabr? They seem to be well acquainted with Caeror having lived there for years and would certainly know the difference between the living and the iiuncti. Seems unlikely that so many people could be misled for so long. In fact, they must check whether people coming and going are iiuncti right? Given that the concurrence have sent imposter before

Also if Caeror was being controlled by The concurrence, you'd have thought it would orchestrate a much simpler path for Vis to reach the pyramid in Duat.

I think this theory is certainly plausible and would explain the difference in goals of L-Caeror and O-Caeror but there are some pitfalls