Well, to be fair, Saracen isn’t an ethnicity but a catch-all Medieval English term for “Muslim person encountered during the Crusades” so not just Palestinian, Syrian etc. IIRC Azeem states he’s a Moor (which was also a medieval English term for any Muslim with dark skin) which probably means he’s from the Maghreb region of North Africa and is more or less the correct ethnicity.Whilst D&D was probably an influence on Robin of Sherwood, Unearthed Arcana was published in the same year, 1985, and was therefore too late.
NB Morgan Freeman may not be white, but he was still the wrong ethnicity for a Saracen.