@man_s_our all mods that are related to the creation of new civilizations depend on a good level of work and time to be carried out, the good side is that much of what these civs need can (and should) be reused from other mods or even from the main game, see in particular Umayyad civ from Millenium AD - REVAMP, they need better models for the buildings, they weren't one of my most inspired creations, Middle Eastern architecture is very different from what I did with Mayans or Japanese. If you need tips, don't hesitate to send messages.