I think more factors than ethnic group or race play a part in penis size...
However, I will add that Richard Burton, not the actor, discussed African penis size in a few of his writings from the, I think, 19th century. I believe the information is in Latin, however he suggested Arab penis size to be a rival of sub-saharan African penis size, which was the largest type he had seen at that point, or ever.
Oh, and they do eat pussy. Happy to report that an Egyptian and Yemeni/Djibouti Arab have both happily, enthusiastically licked my box.