I think al-Andalus is represented by Berbers, no?
Ofc we could talk about a Berber split, but atm I don’t see a reaspn tosplit them for Balance reasons
Ofc there is the potential to crack up the generous Cheaper Stable units into two different stable bonusses. But this would result in both cracked up civs needing some eco bonusses as compensation.
But I would see no issue in adding both Aragnoese and al-Andalus in one patch, probably together with another civ from vastly the same region in north western africa.
This would also open the option to change the Genitour design and give it to the civs that actually used it against the Berbers. One such idea can be found in my concept for an Aragonese civ here .