I love that you've updated the Arabic script (using dots for the emphatic letters and backwards apostrophes for 'ayn), but I wish you'd be more consistent with it. Half of the names show assimilation of the al- prefix (e.g., ar-Rayn, ad-Dawāsir), but half of them don't (e.g., al-Shammar al-Sudayr). The L should assimilate if the noun begins with a D, T, S, Z, R or N.
Also, why do you sometimes use transliteration of the Arabic for cultures (like Hijāzī) but sometimes leave it English (like Yemeni). It would probably make most sense to use the English for all culture names (so Hijazi or Hejazi both of which are fully acceptable spellings in English).