OK, I figured it out after I sent that. It's late here.
The trick is to put a hidden number after each case of al-Zubayr:
al-Zubayr1 family
al-Zubayr2, Ahmad
al-Zubayr3, Mahmud
al-Zubayr4, Qasim
If only the material in this index were so easily solved.
Happy indexing!