Well it seems reasonable for me to toss in a response to this version too. My overall response isn't much different in terms of the general errors of how CK uses religions as a game mechanic, but some of these changes are at least interesting.

Mazdayasna might have the most interesting change to me, going from an emphasis on Angra Mainyu to Aka Manah. Angra Mainyu (aka Ahriman) is overwhelmingly the chief Evil Spirit, that's literally what the name means. Aka Manah (aka Akoman) can be taken one of two ways: In the abstract it literally means "evil thoughts," a direct opposite of the manthra "good thoughts, good words, good deeds." In that way, it's an accurate enough catchall. As a name, Aka Manah is a specific daiva, a particularly heinous and reviled one, but not the chief source of evil. Interestingly, in the Gathas, the oldest parts of the Avesta, Aka Manah is invoked as a source of evil several times, but Angra Mainyu is not mentioned by name. Whether this is out of taboo, because there are missing Gathas, or because the role of Aka Manah and Angra Mainyu shifted over time is up to interpretation.

Behdin, from the Avestan phrase "vanjuhi daena" literally means "good religion," and is a typical term for the community as a whole (sorta, kinda, similar-ish to the Muslims and the "dar al-Islam"). For the most part, the new description is accurate enough, though not true at all times. For example, when the Sassanid Empire still ruled and a centralized Zoroastrian state was directing things, groups like the Mazdakites and Armenian "Arewordik" were explicitly persecuted for their heterodoxy.

Khuramazdism hasn't changed that much in practice, but eliminating the reference to the Vedas and providing more detail about Sogdiana's geo-social position in history does make it a more accurate appraisal, imo.

Khuramism's description hasn't changed.

Khorramdin is just the un-anglicized word for Khuramites, and this might be the description in here that is most misplaced. No doubt, a few generations earlier and among more orthodox Zoroastrians in the rest of Iran, the Khorramadin would have been viewed that way, but their conflicts were primarily with the Caliphates, not their co-religionists. Based on history, that buff against co-religionists would be better suited to Mazdakism, which was actively persecuted in its day.

Afridunism is new and weird. I really can't place a specific Zoroastrian or Zoroastrian adjacent movement that they're going for. The description is reminiscent of many Khorramdin-adjacent movements as well as some of the Parthian-era petty kingdoms in and around Daylam. The name Afridun is just the Arabization of the ancient hero Fereydun, but I'm not aware of any cultic worship centered on him specifically, even in antiquity.

Behafaridism is unchanged.

Gayomartianism is just identical to the old Gayomarthianism with better transliteration.

Mazdakism both adds and subtracts in historical accuracy. As an academic, it's nice to see reference to Zaradust-e Khuragan, as more studies on the topic are trying to extrapolate information about Mazdak's teacher these days. The five "demons" are an interesting item. Those are all vices that the Mazdakites are said to have identified in their society, but not as specific demons/daiva, just things that the daiva spread.

Arewordik is unchanged.