I'm sorry, but that's a ridiculous position. All the John Frum example does is show what is possible. It's not evidence for anything. But I've tried to explain this before.
Look up the concept of analogy as it applies to historical anthropology sometime.
"Belief in Christ is no more or less rational than belief in John Frum." -
Worsley, Peter (1957) The Trumpet Shall Sound: A Study of "Cargo" Cults in Melanesia London: Macgibbon & Kee pp. 153–9.
"Unlike the cult of Jesus, the origins of which are not reliably attested, we can see the whole course of events laid out before our eyes (and even here, as we shall see, some details are now lost). It is fascinating to guess that the cult of Christianity almost certainly began in very much the same way, and spread initially at the same high speed. [...] John Frum, if he existed at all, did so within living memory. Yet, even for so recent a possibility, it is not certain whether he lived at all." - Dawkins Richard (2006) The God Delusion pgs 202-203
"Further supporting the previous element is the fact that what are now called 'Cargo Cults' are the modern movement most culturally and socially similar to earliest Christianity, so much so that Christianity is best understood in light of them." - Carrier, Richard (2014) Element 29 On the Historicity of Jesus Sheffield Phoenix Press ISBN 978-1-909697-49-2 pg 159
And Carrier cites Worsley regarding this like crazy in his book.
Ben C Smith has compiled a list of good reasons to see why Paul regarding Jesus as a near contemporary makes best sense of the data.
And
Guiart, Jean (1952) "John Frum Movement in Tanna" Oceania Vol 22 No 3 pg 165-177 shows what that is NOT the case. There is NOTHING in Paul that shows the Jesus he is seeing is near contemporary. As I said Paul carefully avoids such statement prefering to say rulers of this age and other vague things.
If Jesus was a near contemporary then why not say 'in the time of Pontius Pilate' or 'in the time of Tiberius' instead of vague things like 'this age'? The author of 1 Timothy who is NOT Paul had no problem but that work is
generally dated 100-150 CE despite the epistle claiming in its own text to be from Paul.
In term of Historical Anthropology there is nothing in the seven epistle that clearly shows Jesus to be a near contemporary. In fact if such evidence did exist Mead would have had to address is in his 1903
Did Jesus Live 100 B.C.? but the only things he takes on are 1 Timothy, Acts, and the four Gospels.
And Mead presents the radical Dutch School idea with this comment "I do this the more readily because it conflicts with my own previously expressed view that the
ten Letters of the Marcionite collection were largely authentic."
A little later on Mead says this: "But to return to our reference to Pilate in 1 Timothy. We see that there is no reason why we should assign an early date to this Letter, and every reason why we should hesitate to do so. Marcion (about 140 A.D.) says nothing about it;
it was not in his Pauline canon. That is of course negative evidence, but of positive we have none."
So Mead is pitching out the idea that 1 Timothy as being from Paul and since Mead is not really messing around with the Seven there is nothing in them that clearly puts Jesus as a near contemporary of Paul otherwise Mead would have addressed it. QED.