I really must emphasize again that secondary orality in our literate culture has nothing to do with orality in a rhetorical or transition culture. They are different beasts entirely. Dunn is not wrong to make the emphasis he does. Orality in our culture (=secondary orality) is completely dependent on literacy and the literate mind or consciousness. This is not the case in rhetorical cultures which are dependent on the oral mind.
Rhetorical cultures are not the same as literate cultures like ours. They are transitional cultures. They are cultures where almost everyone is illiterate, except for a minority. Even the minority who are literate, are not literate like we are literate. They have a different consciousness. They retain an oral consciousness. They handle written texts like they handle oral texts, and they handle writing like they do speaking. If you want a good example of what this means, I recommend reading Amin Sweeney, A Full Hearing: Orality and Literacy in the Malay World. I posted a full BOOK NOTE HERE<<< on this last year, and discussed how this might help us to think through the Synoptic Problem.
The literate people in oral cultures do tend to end up the leaders, although this does not mean that all leaders were literate, or that all missionaries were literate. But it does mean that the people who were literate had more power, were seen as "magical," and they controlled the traditions for future generations.
"According to the scriptures" doesn't mean they were reading. Most of the time they were remembering what the scripture said - what they had heard read or recited to them, or what they may have read at some point.