sounds good if their a male and female conjoined pair and 'sheir' and 'shey' are kinda excessive because to me 'they' and 'their' is used for any gender so it seems a bit odd. but thats just me. i have a different method of thinking and seeing things

i'd stick with they/their as it would cover more of a generalized populus plus it doesnt assume a multifur with both male and female characteristics is of a particular gender combination

An interesting idea, but it treads on the 'calling a rabbit a smeep' writer's fallacy. 'They', 'Their'. and 'Them', are gender-neutral.

Agreed. We already have singular and plural pronouns. Unless you want to come up with a specific pronoun for a conjoined pair - which seems unnecessary as existing pronouns do the job - it seems sufficient to use what we have.

Say you have Bob and Ben. "He" can refer to either of them, "They" can refer to both. Now let's change it up, it's Bob and Jen. "He" can refer to Bob, "She" to Jen, "They" to both. Unless you feel there is a linguistic need to come up with a word for the combined Bob-and-Jen entity, it's enough as-is.

As for that linguistic need, it strikes me as needless nit-picking. I get that, if you're trying to depict a society wherein conjoinment has been a major part of its existence, I understand why, in that society's language, there would be a word for the conjoined pair. But any story you tell about that society is told in the narrator's language, not the society's language. It's fine when you have a word for which there is no ready translation, (see e.g. "grok," Stranger in a Strange Land) but when we already have genderless plural pronouns, it just seems unnecessary.

I'm looking at it from a linguistic perspective, not a narrative one. Having separate pronouns for male, female and plural is common in languages of different origins. So if there seems to be a common need to differentiate them, it would seem reasonable to assume that if conjoined people are normal the array of pronouns would follow.

I suppose the question, at that point, is this: would the possible need, to distinguish whether or not a group of people is conjoined, be so great/urgent as to require shorthand in the form of additional pronouns?

Watch your pronouns, though, when in other cultures. The Sweedish have "hen" as a gender-unknown pronoun.

That doesn't seem very relevant to me assuming in Sweden they'd be speaking swedish, not english

I would just stick with plural pronouns on they themselves want something else. If I want to refer to a specific individual, much like real life, I would use their name.