Falcon,
(Step one: you are talking about the Long Sun series, rather than the Short Sun series.)
I don't know that it is "old hat," but then again I don't remember anybody else besides Robert Borski (and lately myself) following this. We have been saying that Oreb is ridden by a god, sometimes, but not all the time; just as Chenille is (sometimes ridden by Kypris); just as Tick is (sometimes ridden by Sphigx).
Then again, we have read "The Night Chough" (collected in THE CROW: SHATTERED LIVES AND BROKEN DREAMS), and you probably have not. <g>
We have some ideas of which god or gods are sometimes riding Oreb, but the short list does not include Pas in any way, shape, or form. Top of the list is Scylla.
And yes, this does complicate things throughout TBOTLS!
=mantis=
P.S. We use these abbreviations so much and so long that lately I've toyed with the verbal forms, to wit:
TBOTNS: "bones"
TBOTLS: "bottles"
TBOTSS: "boss"
=m=
*This is WHORL, for discussion of Gene Wolfe's Book of the Long Sun.