The Dervish State
Abdullah Hassan
The Horn Resistance
+1

Faith from Forts and Citadels and they provide

Great Engineer points to the Capital upon construction, but may not be removed. Gain

Great Writer points from killing land units. Mounted units earn special Promotions based on their level.
Maara-weyn
Available earlier than the Anti-aircraft gun it replaces, but has no combat bonus against aircraft, and does not intercept. Faster, but requires Horses. Can move after attacking, but receives a combat penalty (-33%) against cities. Receives a combat bonus (+15%) if stacked with a

Great Writer. May be upgraded to from Cavalry.
Qalcad
Provides XP to newly trained units in the city based on the amount of Desert tiles in your territory (up to 15 XP), unlike the Military Base it replaces. Provides 1

Great Engineer point to the Capital.