I will take your first branch: Mental states are not observable, certainly not in a way which gives rise to some measure which we can call "orderedness". Study psychopathy and you'll see extremely "ordered" behaviors from people who are "suffering" from "mental disorders". At some point, the analogy becomes incoherent; human behaviors are too rich.
You may be interested in Aumann's Agreement: If two reasoners disagree, then either their reasoning differs, or their prior observations differ. It seems to me that typically it is the priors that differ. So why stigmatize folks for differing reasoning? Perhaps there is no good reason.
I can observe my own mental states, and I work to bring them into better alignment with my observations - more ordered. When I think it helpful to others, I use language to represent them. Because other's mental states are not directly obervable, I use a null hypothesis that they also use language to indicate their mental state.
When I use a regular expression, I have an intent to model an understanding. Some people may not have that vocabulary at all - my spouse, for instance. Some may be far more fluent than I. The point is: I have observed my understanding to be disordered or incomplete. I further observe that is the default state until I apply a degree of attention.
"Stigma" is an inaccurate model for when we don't have the resources to align another's goals with our own - goals which must include a baseline of wellbeing for every other. Persons suffering harmful hallucinations - or other harmful mental states - should be treated for them, but "stigma" is a blunt indicator to avoid conferring responsibility on those persons - I hold it an error to involve hatred or indifference. Our deficiencies in understanding are pervasive. I would not ask my spouse to develop a regular expression. They would not ask me to perform a phrase from a Mozart sonata.
You may be interested in Aumann's Agreement: If two reasoners disagree, then either their reasoning differs, or their prior observations differ. It seems to me that typically it is the priors that differ. So why stigmatize folks for differing reasoning? Perhaps there is no good reason.