Adding information to #Wikidata means that you want to use the existing items with interwiki information. When you find red links in the English Wikipedia, it is easy to think that there is no information in Wikipedia. It really pays to check the interwiki links of the article that contains all the red links.
The Catalan Wikipedia I find is really good at providing information on the Islamic rulers that are part of Spanish and North African history.It means that when I add information I need to take their existing articles in consideration.
I got the impression that the Zayyadin dynasty were "caliphs". So I created an "Zayyadin caliph" item. My hope is that someone will change it to "emirs" when this is wrong.