I am not fond of the Butr/Branes distinction within the Berber group. The Butr/Branes is a rather inconsistent distinction made by Arab historians based on, to make it short, two criteria:
- the way of life, Butr Berbers being essentially nomads while Branes were settled Berbers.
- the fact that they rallied quickly or not the Arabs during the Arab conquest, Butr Berbers from Libya, the Aures (Eastern Algeria) and Miknassa (Central Morocco) being among the first Berber groups to convert to Islam and to join the Muslim army (especially during the conquest of Spain) while Branes only did it a bit later and converted gradually.
Berber themselves much preferred a tripartite/quadripartite distinction between Masmuda (mainly Morocco), Sanhaja (mainly Sahara and large part and current Algeria. Distinctive feature: women had higher social status and some Sanhaja groups were even matrilinear, like modern Tuaregs), Zenata (who were indeed mainly nomads, but some of them settled in Libya, Southern Tunisia, the Aures Mountains and later on in the Rif) and Huwwara, who were kin to the Zenata. Linguistics also attest that the Zenata/Sanhaja/Masmuda classification is more relevant, although not flawless.
First of all, I will prefer to use spelling and naming used in respected academic sources such as Historical dictionary of the Berbers or Encyclopedia of Islam, hence I will use Baranis instead of Branes (which is how mainly Morrocans - not always perfectly familiar with English transcription rules - spell the Baranis).
There are several problems with division of Berbers.
As you said, probably the firsct choice really would be the 3-fold division into Masmuda, Sanhaja and Zanata. This division, although historically accurate, does have numerous flaws:
- there are too many groups which remain outside this division. The Kutama, the Hawwara, the Lawata (and quite a few other) large and important groups are related to some of the major confederations, but weren't really neither Sanhaja nor Zanata, nor Masmuda.
- there's a problem of differences - both a) between the groups and b) within the groups themselves.
b) In terms of lifestyle the Sanhaja of Ifrikiya were totally different people than the Sanhaja from the Sahara, AKA the Veiled Sanhaja, the tribes of Lamtuna, Guddala, Massufa, who led the Almoravid movement. While the first ones were sedentary population, the other were nomads par excellence, with very different cultural features - like the position of women, clothing etc. - which weren't common among the Sanhaja from Ifrikiya.
a) Despite deep anomisities and ofen hatred between the Sanhaja and Zanata, as well as Masmuda, if we look at cultural signs such as naming conventions, we can see that the tribes, clans and dynasties for which he have historical records, we can see that they weren't different. In the 10-11th century we can see that there was a wave of newly popular names among various Berber dynasties, but we can also see that the same names were popular both among Zanata tribes as well as among the Sanhajas, while other tribes from all groups prefered to use different naming patterns - this all worked across the Masmuda/Sanhaja/Zanata tribal confederations.
- the other cultural signs important for this game, such as cultural customs, legal and other traditions or military traditions and preferences were all different for various tribes, but very often didn't respect the Masmuda/Sanhaja/Zanata confederation split
- furthemore even the blood feuds and animosities did not always follow the confederational split, as there were cases of Sanhaja tribes allying with some Zanatas against other Sanhajas, Sanhaja families or clans joining Masmuda tribes and vice versa
Still, when I did a setup for SWMH map/cultural mod for Historical Immersion Project, I used the Masmuda/Sanhaja/Zanata division and expanded it a bit. Separated the desert Sanhaja into artificial
Tagelmust (The veiled ones) culture, added anachronistic Touarages (
because they are too cool and popular to be ignored), and we added the Guanche. Still this left us with having Zanata ahistorically in western Egypt, we had to merge the other big groups with these (I didn't want to create "Other Berbers" group for them) and still it didn't ideally model the situation and the groups tended to eliminate each other way too often instead of living next to each other.
So in accord with my suggestion to deal with the desert people (the Qabila DLC suggestion in my signature), I later prefered some simpler division, which would still fit the concept, respect the different patterns in lifestyle as well as waging war, which are the features which are essential in Crusader kings. And the 2 fold division into nomads and sedentaries was ideal. Then when the CK2 team started reworking the Maghreb and I was asked to help them with sources, I suggested the 2, respectively 3 possibilities (Butr/Baranis or Sanhaja/Masmuda/Zanata or Sanhaja/Masmuda/Zanata/Guanche/Touareg/Tagelmust/?Others) and after some discussion, the choice was made to have Butr/Baranis.. but it was too late to do everything necessary, so they remained as just one culture.... and the division was implemented later, for CK3.
It has its flaws too, I admit, but considering that cultures are primarily a tool for gameplay and considering how they worked in CK2, this seemed like a better solution. And with the way how cultures work in CK3 I think it is even better, although still not ideal.
to add to yuor point, in a way, it seems that the Butr/Branes destinction also represents a degree of pre-islamic culture, at the verry least it *must*, otherwise the adition of magrebi becomes somewhat nonsensical (if i'm understanding the terminology right) in this screenshot from 1066
View attachment 579873
The Maghrebi group obviously would be the long-demanded "melting-pot-culture" to represent Arabs or other non-Berber Arabized people living in the Maghreb who - although not being always Arabs - spoke and behave as Arab aristocracy/rulers, but were mixing with Berbers. People were asking for this group to be included and separated from Berbers for years - here they seem to represent the starting Arabization of Maghreb by the Hilali invasion.