Eek! I don't know how I missed your comments for so long! Sorry about that...
You're right, to a Cardassian, Yejain's hierarchical instinct is considered particularly pronounced. Not abnormal, but certainly a distinguishing characteristic of his personality.
Illogic makes Yejain mad. (Which proves he's no Vulcan.) And that's how the Obsidian Order pushed his buttons--by failing to follow any kind of sensible order from cause to consequence. You could easily imagine Yejain as a father; I imagine he's very measured in the same way towards his children...he doesn't let them get out of line, but he makes the punishment fit the "crime" and doesn't think it's necessary to break them to make sure they learn. He would find that
a punishment so far beyond the small transgressions typical children commit that it would horrify him.
It's interesting that you bring up the autism comparison...while the rigidity, by human standards, could seem to lead that way, in contrast, the hierarchical instinct strongly impacts social relationships and makes knowing the rules a bit more of an inborn thing for Cardassians than it is to humans. I actually think to a Cardassian, a human could look as if he or she were a little bit on the autism spectrum due to the failure to give some of the "right" tones, gestures, and responses according to various spoken and unspoken cues.
As to learning disabilities and even the Cardassian equivalent of autism spectrum disorders, you actually have met one Cardassian with a learning disability already, and that's Gul Berat. If you compensated for the differences in his alien psychology, Gul Berat would show clear
indications of ADHD. (Did you notice Yejain trying to steer Berat's interest towards the paperwork, a bit? He knows his gul needs a little bit of encouragement for such tasks.
About Daro, I didn't want Daro to sound bigoted or like he was looking at humans as the be-all-end-all, as someone like Picard seemed to want. So I'm glad that part came off well to you. Daro sees strengths and weaknesses in both ways, but I get the feeling that he secretly enjoys the uniqueness of all the different species he's encountering. He's an academic by nature--not quite the analyst
Yejain is, not as much the need to acquire every fact so that it can be put in its proper order; I think for him, it's a quiet curiosity for the sake of it.
I am so glad the humor came across as funny! That's one of the things I feel the most self-conscious about writing, because it doesn't come naturally to me at all, and I consider it to be one of my weak areas.
But yeah...after the Obsidian Order--and also with Berat a little bit tense because of the talk in the mess hall that didn't go so well--I didn't think Berat was likely to see the humor in the "no good deed goes unpunished" saying, only the sarcasm. (Though he wasn't so tense that a solid explanation wouldn't "defuse" him.)