After my second and admittedly, more careful read, I noticed that Nin'Ciljaris refers to Yatwer as the "Fertility Principle". As if the Nonmen regard Yatwer as an abstraction that explains the miraculous; wombs quicken and therefore, there must be a greater power behind it.
This makes makes me think that the Nonmen more or less know exactly what's going on with the Gods. And all the evidence points to their being terrified about it to the point where their goal, seeking Oblivion, is all about avoiding them.