This is the exact opposite of reality in every possible way. The Miaphysites aren’t just reformed, they were probably more reformed than literally any other Christian religion. By the first start date Catholicism and Eastern Orthodoxy both have a lot of changes in coming years, namely the Great Schism, Meanwhile the Miaphysites, since their split in 451 from the main churches, has been stable in every doctrine. As a Coptic Christian I can say that we still read the Nicene Creed... from the first council in 325, to this day, some of the oldest bible manuscripts are written in Sahidic Coptic. The first monk and monastic tradition originated in Egypt with St.Anthony. In Catholicism and Eastern Orthodoxy even after the split they still revered St.Athanasius and St.Cyril as fathers of the religion.
To say they were unreformed, or as you put it ‘unorganized’ (I assume you mean no real leader), is the same as saying that a religion that gave ALL of Christianity some of its most recognized features, like monks and doctrines from the 1st and 3rd Councils before their split, and SURVIVED 1400 years under Islamic Rule without being wiped out or changing Doctrine.
To handle the meat of your statement, no the Coptic Pope (It’s more accurate to say Patriarch of Alexandria, he is a bishop with equal power to any other except for the fact that Alexandria is revered as a holy city) definitely without a doubt had power. I have an entire thread I dedicated to Miaphysites below, and their you’ll find some examples of how relevant the Coptic Pope Was.
https://forum.paradoxplaza.com/foru...es-egypt-and-revolts-recommendations.1272183/
And now to more relevant arguments, Miaphysites have a very stable and very very clear leadership. They’re lead by 4 Autocephalous churches in this time period (Coptic, Armenian, Malankara(India), and Syria) who all have EQUAL power, and since their respective Patriarchs have only a Bishop position, all bishops are equal. However far from their being no clear leader, a Patriarch had extra powers than a normal Bishop, the very term ‘Patriarch’ means ‘Patri’ Greek:Father ‘arch’ like an arch bishop, he is the father of the Bishops, the highest rank of Bishop and has powers granted to him by the Holy Synod.
Here’s a link on the Coptic Pope:
https://en.m.wikipedia.org/wiki/Pope_of_the_Coptic_Orthodox_Church_of_Alexandria
Among duties important to the game the Coptic Pope can Consecrate Bishops, Consecrate Churches (My own church had to wait 4 years until his H.H. Tawadros II could come) , and Canonizing Saints. The other Ecumenical Patriarchs I would assume have similar abilities.
Finally, where the hell did you hear Miaphysites in Africa were Tribal? The two centers for Christianity in Africa, Egypt and Ethiopia, both Coptic, were centered around the massive cities of Alexandria and Aksum, neither of which were tribal. Tribalism in Africa is mainly in West and Sub-Saharan Africa, Sudan had a few tribes, buy even then Ethiopia and Egypt were light years from being Tribal. Also what do you mean ‘mass conversion’ is ‘fitting’, not sure if you’re aware but after splitting from the other churches the Byzantine Empire DID try mass-conversion of the ‘heretics’ (They realized that not only we aren’t heretics, but have literally near identical doctrines 1400 later when our Patriarchs professed one faith and began the path to ending the schism in 2001) and failed miserable despite hundreds of thousands dying in mass persecution. By the time Islam conquered Egypt in 642 the 200 years of persecution failed and Egypt was still more or less 100% Miaphysite despite the genocides. Also not sure if you’re Eurocentric or just wording it wrong but what the hell is a ‘stronger religion’ supposed to mean? With Ethiopia being included in the map update supposedly Miaphysites will be WAAAAY more relevant, why convert to Catholicism when you have so many other Coptic Countries to interact with, plus assuming the feature is implemented realistically mass conversion wouldn’t convert your provinces automatically and all you would get is a bunch of revolt risk for being of a different religion.
Anyway in summary the Miaphysites do have leaders (I agree that CkIII should distinguish between Armenian and Coptic Autocephalous branches since each had their own power, however they were still one religion and be displayed as such) who do have mechanics that Ck3 should (at least Ck2 did) represent. And in any case were very organized and reformed, with little to no change in doctrine in 1600 years and the very least more religiously stable than the Catholic and Eastern Orthodox churches dealing with the Great Schism.