Because we certainly would not be able to make new units for all factions on the map we have tried to make more interesting rosters for the more exotic factions by 'extracting' from the Vanilla units and their upgrade models those that would be least awkward and give them new roles. Here are the first examples:
al-Murabitun (the Moors)
Berbers
The Berbers would be the core population. They are available in Africa and Spain, but as a highly mobile people, would follow the Moors to every conquered province


Berber Tribal Horsemen, Berber Tribal Warriors and
Berber Noble Guards
Arabs
Arabs live in Africa, the Levante, Spain and Southern Italy.
Arabian Tribal Warriors
with archers, skirmishers and spearmen.

Arabian Urban Militia and
Arabian Raiders
the unit in game has horses
Faris and
Noble Faris
(the mounted versions only)
Taifa
This is the military of the
Taifa states that dominated Spain since the collapse of the Cordoban Caliphate. They mix elements of European and Oriental warfare. They are available in Spain only.
Taifa Garrisons and
Taifa Crossbowmen.
Even though the Arabs prefered the bow over the crossbow, crossbows became rather popular for castle garrions in Spain.


Taifa Horse Archers, Taifa Horsemen and
Taifa Nobles.
These would be the core units of the Taifa states.

Taifa Urban Militia and
Taifa Volunteer Swordsmen
Ghazawatun
These are only available on Jihad
Ghazawat Archers and
Ghazawatun
Muwalladun
These are (former) Christian nobles that converted to keep their lands and titles. They are available in small numbers in Catholic regions.
Muwalladun and Dismounted Muwalladun.
African Mercenaries
Mercs from sub-Sahara Africa are available in rather limited numbers in N-Africa and the Levante.
African Warriors, African Skirmishers and
African Archers.
al-Salajiqa al-Rum (the Turks)
The Turks are a complete different people to the Arabs and Berbers, there would also had not been any Arab population of notable numbers in Anatolia, so their units cannot be the same as those of the "Moors".
Iqta'dar
These feudal units would have formed the backbone of any Turkish army

Seljuk Nobles and
Turkish Horse Archers
The Seljuk Nobles would also become the new bodyguard for the Turks. The unit in game has horse armour.
Levy
These were often raised in large numbers by the nobles in order to fullfill their quota in troops to deploy for the Sultan.

Herdsmen and
Dismounted Herdsmen.
Ghilman
These are war-slaves. The usage of slaves as household troops had a long tradition in the Near East; but the Seljuks of Rum had never been as rich as the Egyptian Ayyubids or the later Ottomans. That way their war-slaves did not become as important as the Mamluks or the Janissary.
Ghilman Archers and
Ghilman Horse Archers.
Ghilman Raiders and
Ghilman Spearmen.
Turkomen
These are Turkish mercenaries from Central Asia available in the south-east of the map.


Turkoman Horse Archers.
Turkoman Raiders.
Turkoman Lancers