Spot on Jurble, I also got this feeling during my first read.
Stuff I thought while reading: Why would they expose and endanger all 5 Dunyain? I think it's a fair Dunyainly assumption that upon finding a Consult Dunyain, Khellus is going to at least tolerate some amount of an exchange of words before insta-killing, some bare minimum question asking/information gathering/plan assessing of some degree. How could he not, right?
So if these "five Dunyain" were expecting a conversation to occur here, I don't see any need for more than one Dunyain to chat with Khellus, and exposing the fact that there are more and exposing ALL of them (indeed, it appears Khellus assumes there are only these 5) is needless/dumb/unDunyainly.
If "they" were anticipating combat I also think letting Khellus size them up isn't a very Dunyainly thing to do even if some number of them (obviously true for at least 1) could sing Sorcery (Khellus didn't see any Marks that we read about, so no reason to assume he could locate them prior to them revealing themselves, even if all are of the Few). If 4 of these Dunyain (who all know the Ark - and this room has many entrances, recall) could've prepared for a much more tactical approach, it seems in-Dunyainly to me just all walk out at once.
Even disregarding the above though, "their" speech patterns immediately confirmed for me that these "Dunyain" were Shae; it was actually their speech patterns that triggered me to more closely examine the situation and brought about my above suspicions.
Now with the death of one of his "bodies", I'm wondering how such a death will affect him (or indeed, if it even does).
Speaking of... haven't we seen Shae with ten "bodies" so far? At least in TUC, that's the number of Larval bodies in the illusion. Got a feeling as well from the word "subsume"!
Even if we assume that Dunyain bodies are in some way better than the wretches that Shae used to inhabit, such that five is "enough" to house him - would five be "enough" for Shae/the Consult overall? And back to my initial skepticism with it being stupid to reveal all five: if you were Super-Shae with Dunyain-level intelligence, would you put all five of your pieces on the table directly in front of Khellus knowing that if he manages to destroy all five, you're going straight to the hell you've been avoiding for millennia? ("You didn't like the pantomime, heeeere I aaaaam!")
Four remaining "Consult Dunyain" sounds good considering Horsemen and the number of Ajokli's horns, but does sounding likely count for much here? Food for thought!