Who Was Rav Papa?

Rav Nachum Bar Papa is mentioned in Yoma (67a) on a daf that was recently learned by Daf Yomi participants. What he was quoted as saying is certainly important. Yet, some commentators chose to focus on the name itself. Was there really an individual named Rav Nachum Bar Papa? Why would one even question this fact?
The names of Rav Papa’s sons are recited at every siyum. Rav Nachum is not listed there as one of the sons. If he did exist, why didn’t he make the list? Some commentators suggest a slight textual change to conform with a name that is on the list. Still, others suggest he was known by two names and that his alter ego made the siyum list. A rather simple answer offered is that Rav Nachum was not the son of the famous Rav Papa mentioned all over Shas but was the son of a different person named Papa.
Why did Rav Papa, in fact, merit having the names of his sons recited at every siyum of a Mesechta?
Rav Shimoshon Aharon Polinsky suggested that the answer to this enigma is spread all over Shas.