So the encyclopedia book Darth Maul and Other Dark Side Followers established the existence of both Third Sister and a Third Brother. I thought this established that a male and female Inquisitor may share a number (so there would exist a Second Brother, Fourth Brother, Fifth Sister, Sixth Sister, Seventh Brother, Eighth Sister, Ninth Brother, and Tenth Sister). But some people are saying that Third Sister's introduction in the Kenobi show retcons the existence of a Third Brother. If the book only introduced Third Brother, then this may be plausible, but it introduced both Third Brother and Third Sister (at least according to Wookieepedia; I don't have access to the book so I never confirmed for myself). Although on the flip side, it does seem odd that only one Inquisitor has been assigned to each number for this long (the first mention of both a male and female Inquisitor being assigned to the same number happening 7 years after the Inquisitors were first introduced). I wanted to know what people here think about this topic.
Initially, the question, is whether the name of an inquisitor is for instance, third "brother" or "third brother". The former is a generic name, while the former is a specific one. In either case however, the third "sister" or "third sister" would be different than third "brother" or "third brother."
I'm thinking no just because of what we've seen so far. If anything new comes out that contradicts that, then so be it. Reference books aren't solid canon. With how the canon has evolved, they're like using a wikipedia article as a source in a scholarly paper. Even if there is mention of a Third Brother in a reference book, we haven't been introduced to one on screen or even in a novel or comic. There have been vague hints to a ranking system within the Inquisitorious, mainly I'm thinking in that one Rebels episode where Fifth Brother chastises Seventh Sister when she stops him from killing Ezra, Fifth Brother claiming "the kill is mine" addressing Seventh Sister in that instance.