Qadhi Abu ‘Abdillah As-Saymaree (rahimahullah) narrates the following from Imaam Abu Yusuf (rahimahullah):

Imaam Abu Hanifah (rahimahullah) was once asked regarding the two renowned students of Hazrat ‘Abdullah bin Mas’ood (radhiyallahu ‘anhu), “Who is greater, Hazrat ‘Alqamah (rahimahullah) or Hazrat Aswad (rahimahullah)?” Imaam Abu Hanifah (rahimahullah) replied, “By Allah! I am only worthy of taking their names by making du‘aa and istighfaar for them (that Allah Ta‘ala raise them in the Hereafter and overlook their shortcomings) out of respect for them, so how can I judge who is greater between them?”

(‘Uqood-ul-Jummaan pg. 227)