Did AD 30-70 churches orally teach and pass down Jesus-biography in an adeptly preservation-oriented way?

While many eyewitnesses were still alive an active (e.g. Ad 30-80), were the various Christian groups orally rehearsing, teaching, and sharing the stories of Jesus’s life, ministry, death, and resurrection and a way that would inspire confidence in us that the stories were passed down faithfully? Rather than being passed down like information in the children’s “telephone” game, did Christians exercise a kind of care in relaying and preserving Jesus-stories which would result in their being faithfully presented abroad even several decades after they were first circulating?

• Richard Swinburne: “I made the point earlier that the other Gospel writers belonged to churches founded and visited by representatives of more central churches, themselves founded or authorized indirectly by the apostles. They were founded and reinvigorated by a stream of oral tradition. Gospels were written to flesh out the tradition, and to ensure that, with the course of time, it did not get misreported. But they were not the primary vehicles of its transmission in the first fifty years. No one founded a church as a result of having bought a copy of St Mark’s Gospel from the local bookstore and being impressed by its message!” [The Resurrection of God Incarnate (Clarendon, 2003), 80-81.]
• Michael Bird: “[t]he tradition is ultimately a memory and that memory is transmitted and transformed by a mnemonic process of both individuals and groups. Such a model also enables us to unify the elements of bias and biography, to uncover a memory that is reliable but also refracted. Aided by eyewitnesses, teachers, a discernible process of handing-on and receiving traditions, and a rich mix of oral mnemonics and textual aide-mémoire, the early church remembered Jesus, recounting him as a Judean sage as much as a divine Savior.” [The Gospel of the Lord (Eerdmans, 2014), 61.]

Ehrman's “Form Critical” model says it like the children’s telephone game
• Bart Ehrman: “Anyone who converted to become a follower of Jesus could and did tell the stories. A convert would tell his wife; if she converted, she would tell her neighbor; if she converted, she would tell her husband; if he converted, he would tell his business partner; if he converted, he would take a business trip to another city and tell his business associate; if he converted, he would tell his wife; if she converted, she would tell her neighbor . . . and on and on . . . Who, then, was telling the stories about Jesus? Just the apostles? It can’t have been just the apostles. Eventually, an author heard the stories in his church — say it was “Mark” in the city of Rome. And he wrote his account.” [How Jesus Became God (HarperOne, 2014) 91-92.]
• Bart Ehrman: “[Their info was] fifth- or sixth- or nineteenth-hand,” [Jesus, Interrupted (HarperCollins, 2010), 146-47.]

But scholars have roundly rejected that analogy
• Anthony Le Donne: “It must be said that this [telephone game] is not a controlled exercise in orality. It is an exercise in variation without stability. The vast majority of human civilizations operated with largely illiterate cultures. Are we to imagine that all these civilizations were the equivalent of giggling children? That the golden ages of Egypt, Rome, Britain, the Maya, etcetera had no confidence in the stability of social communication? No. Oral cultures have been capable of tremendous competence. The human mind can remember vast amounts of information with great accuracy when it remains active and fluid. The oral culture in which Jesus was reared trained their brightest children to remember entire libraries of story, law, poetry, song, etcetera.” [Historical Jesus: What Can We Know and How Can We Know It? (Eerdmans, 2011), 70.]
• Craig Blomberg: “Thus when Bart Ehrman likens the transmission of the Jesus-tradition to the children’s game of ‘telephone’ in which a whispered message is quickly distorted as it is passed from one child to the next, he has chosen an utterly inappropriate and irrelevant analogy to what would actually have gone on among first-century Christians!” [The Historical Reliability of the Gospels 2nd ed. (IVP, 2007), 61.]
• Frederick Murphy: “this analogy limps badly.” [Introduction to Jesus and the Gospels (Abingdon, 2005), 22.]

Christian Jesus-bio was ultimately memory
• C.H. Dodd: “...the materials out of which they were formed were already in existence, as an unarticulated wealth of recollections and reminiscences of the words and deeds of [p.88] Jesus―mixed, it may be, with the reflections and interpretations of his followers. It was out of this unformed or fluid tradition that the units of narrative and teaching crystallized into the forms we know. At the early, unformed, stage we have to think, not of discreet narratives, with their individual features sharply marked, as we have them in the gospels, but of a host of remembered traits and turns of expression, often disjoined and without context, but abounding in characteristic detail.... But the precise occasions with which these features of [Jesus’] Ministry were associated were perhaps not always remembered, or were remembered differently by different witnesses; for the association of ideas is a very individual thing, and it often affects our recollection of events.17” [Historical Tradition in the Fourth Gospel]

E.g. Public reading facilitated control
• Craig Keener: “The reading of these earlier texts probably standardized the forms of many of the accounts; communal reading (or reading to the communities) was common in synagogues, churches, and the wider culture. While such a “quality control”may not have been relevant in the composition of Mark, it would likely be relevant to his successors, such as Matthew and Luke, who made use of Mark.” [Christobiography (), .]