Sufi Mosque
The Sufies as such were not a tribe. If not that many tribes were Sufists, which is a different way of practicing Islam.
Current technologies:
Pilgrimage:
It becomes a passive improvement where every 3 minutes 2 goats arrive without getting fat at your metropolis destination, and you receive 2 when performing this improvement immediately.
(In fourth age it can be improved to reduce the delivery time to 2 minutes).
For the Indians it improves the experience gathering of cattle.
For the Japanese it improves the production of the sanctuaries by domestic cattle.
In case of reaching the limit, a limit of 10 stops resiving them
Fasting
It’s fine like this, but instead of reducing the resistance points of the villagers, you should rather slow down their creation.
It could become a button in the town center or trading post, where you can toggle between slowing the creation of villagers to get the bonus or vice versa.
I have been researching the Sufis to find out how to include enhancements that make plot sense. Some believers in this doctrine were nomads and good ranchers.
New technologies:
Pasture: Cattle are cheaper.
The Bedouins are expert herdsmen and they know how to obtain resources for cattle in the desert.
Bedouin families: Villagers have more resistance points and better attack.
The Bedouins teach you how to endure the harsh conditions of the desert and obtain its resources.
The statistics of each improvement are left to the discretion of the developers.
They could include a camel fighting unit if historically feasible. That i would like. 