The problem I'm having is that this doesn't look that different from OTL Europe. I mean, compare the Christian states in Iberia during this period, or France during the Hundred Years War.
It's really, really different.
Hundred Years war by exemple : you have basically three political factions. They were formed not because of the origin, not because of the family (you have many split families because of that, by exemple...the Valois) but because of political interest and changing side became a sport.
In Arabo-Islamic world, while you have too the existence of political factions, they're more numerically important and often unable to unite themselves. Furthermore they played a secondary role in comparison of tribal interests even within a larger tribal situation.
By exemple, in the fight between Qais and Kalbit in early Al-Andalus, you have even inner fights whitin each factions while the civil war is still flaming. And it's only for the Arabs here.
If you search a comparison in western christianity, i would suggest you to employ the exemple of post-carolingian feudality. Here you have too the struggle of families (it's still different from tribal structure that is less open) against other ones for the domination on ONE territory.
Though, it's still different, as the king have a moral power within the said territory, with a capacity to help one side (by giving it legitimacy, "honors"). In Al-Andalus, the emir/caliphe couldn't reasonably do that, except if he lead an army there.
Don't get me wrong, christian king and islamic amir/caliphe have both a capacity of concentrating powers, and a moral ascendent. But while the king was sacred, almost impossible to overthrow if not with the help of another king or serious pretender and being the source of feudal legitimacy by giving the honors; the Caliphe didn't have that.
Depsite his religious title, and even if this one grant him to have his name mentionned during prayers in lands he don't control, his opponents and his rivals don't see him as the source of their power : what they have, it's thanks to them. If the amir/caliphe want to take it back, he could always try.
You'll say me that Al-Andalus is quite a particular situation and you'll be right. The tribal structures disappeared relativly quickly here, in comparison of Arabo-Islamic world, and it was "replaced" by a "originalist" (sorry, don't find a proper word, as it's not "nationalism" nor "racism" stricto sensu) policy.
Depending on how much you was arabized, you had a better place in society. (The amirs and the Caliphes often used it for overthrow their arab rivals, and used mainly muladi, jews, berbers and even christians as councellors and administrations).
In the same time, in Western Europe, at the notable exception of the mediterranean lands (Spain, Occitania, Italy) the minorities didn't participate even to the local scale. And even there, they didn't have an acess to the power itself.Having lands less diverse than Al-Andalus, forming an island of Islamity, the christian lords couldn't play on "origins".
So their society, less tolerant, less open, less socially dynamic were more stables rather than Al-Andalus where the continual bascule play between communauties avoided the creation of a united andalucian. In fact, during the Fitna, you'll have many pogroms, expellation of Christians, mass killing of Berbers...Because Arab and arabized thought their natural legitimacy to rule the country was overthrowed by them wit h the assistance of the Caliphat (which was quickly deleted).
For northern Spain, you've partially right : the familial (i insist, familial isn't tribal) disputes were quite important in the X/XI centuries and degenerated in civil wars. But here, i would think that the regular interventions of the Caliphe, blowing hot and cold. Still, it wasn't as damagable for christian structures, as it was always resolved on a familial base and the pretext (if not the reason) of the civil war often disappeared with the disappearence of the pretender.
The dissenssions in Islamic spain were more lasting (or even permanants) and when the Christian could unite (admitedly, it didn't happened often in the first centuries, but just one time was needed to strike badly the Caliphate or its remnants) they could play easily on it, critically when they were familialy tied with northern families (converted or Arabs).