I'd also postulate that a Dunyain would be significantly worse at the Anagogis than the Gnosis. The Gnosis is basically magical math. It's all very abstract and logic based. The Anagogis gets power from blurred meanings, similarities, and metaphor. Making reality do something different by tricking it into thinking they're the same. Not something the highly deterministic and analytical Dunyain are really good at feeling. Using as tools on people that are vulnerable to them, yes. But at Ishual they crush such self deceptions from their disciples at a young age. I imagine they'd have more talent for it than the Psukhe (if Moenghus truly was weak in it...but I'm not so sure about that.), but the Gnosis is practically ready made for Dunyain consumption. It's everything they train for.
I have to wonder how the Quya differs, though. I got the impression Nonmen are fairly different from men, cognitively. And the Gnosis is just a pale reflection of the Quya that humans picked up during the Tutelage, if I remember correctly.
I also have to wonder about the Aporos. Was it just a subset of lost techniques within the Quya, or an entirely different sorcerous school now lost to all but the Consult?