Thank you very much for your helpful message. I would be very much grateful if we continue communicating with each other, and benefitting from you knowledge of the Ashraafs of Hindustan.
I can confirm to you that Asad ibn Hashim (your ancestor) HAS DEFINATELY begot a son. And his grandson (Abdullah ibn Hunayn ibn Asad) was one of the people that were involved in helping Sayyida Zaynab escape to Madina. He is mentioned in the book (Ansab Al Arab) by the famous Andalucian geneologist Ibn Hazm.