Consider especially this saying of Papias:
//But I shall not be unwilling to put down, along with my interpretations, whatsoever instructions I received with care at any time from the elders, and stored up with care in my memory, assuring you at the same time of their truth. For I did not, like the multitude, take pleasure in those who spoke much, but in those who taught the truth; nor in those who related strange commandments, but in those who rehearsed the commandments given by the Lord to faith, and proceeding from truth itself. If, then, any one who had attended on the elders came, I asked minutely after their sayings,--what Andrew or Peter said, or what was said by Philip, or by Thomas, or by James, or by John, or by Matthew, or by any other of the Lord's disciples: which things Aristion and the presbyter John, the disciples of the Lord, say. For I imagined that what was to be got from books was not so profitable to me as what came from the living and abiding voice.//
I can't resist commenting on this, as I am younger than Bart is, but I have known quite a few people who knew people that have been dead over 100 years. Why, in the recent pandemic, there were people around who had survived the last one, which was over 100 years previous. Papias himself said there was only a single link in the chain connecting him to the apostles. And there have been people alive in the 21st century whose grandfather flourished in the 18th century. I know what my great-great grandfather was doing on his daughter's 13th birthday, 150 years ago, having heard if from someone who heard it from an eyewitness (the daughter). It's rather ludicrous to think that Papias could not have known who wrote the gospels, which were already in circulation under the names they still have. It would be like me not knowing who penned my great-great grandfather's diary 150 years ago, even if his name isn't on the flyleaf.
"In one of the most famous passages quoted by Eusebius, Papias indicates that instead of reading about Jesus and his disciples in books, he preferred hearing a “living voice.” He explains that whenever knowledgeable people came, o visit his church, he talked with them to ask what they knew. Specifically he spoke with people who had been “companions” of those whom he calls “elders” who had earlier been associates with the disciples of Jesus. And so Papias is not himself an eyewitness to Jesus’ life and does not know eyewitnesses. Writing many years later (as much as a century after Jesus’ death), he indicates that he knew people who knew people who knew people who were with Jesus during his life. So it’s not like having firsthand information, or anything close to it. But it’s extremely interesting and enough to make a scholar sit up and take notice."
Sean du Toit
Buck, if only scholars would read some of the older works such as Vincent Taylor, The Formation of the Gospel Tradition (London: Macmillan, 1933), they’d see this type of reasoning.