Historical method puts the question you ask very simply: If you have an ancient writing ─ and it contains a purported prophecy ─ and the purported prophecy is historically correct ─ then which is more likely? ─ that this is the only authentic example of supernatural foreknowledge in the world's literature? ─ or that it was written after the event? The answer is a no-brainer.
The issue with Josephus' account of Jesus son of Ananias is NOT whether the reported prediction is accurate, which is irrelevant BUT whether the author of Mark used it as his model for the trial scene of his own Jesus.
So far as I'm aware, the point was first made by theologian Theodore 'Ted' Weeden jr. in the Jesus Seminars, listing 24 points of parallels in the two accounts. A summary is
>here<.
See. You miss the point. Many mythicists will have their banking practice on parallels for many many things. But what you have done is that in following scholarship that are mythicist at heart, you have ignored the historical approach abruptly.
The historical approach does not take the mythicists approach of taking two or three parallels and then saying one copied from another. This is predominantly a false dilemma. Because there is always a second or/and a third option.
Maybe Josephus inherited from the already existing Jesus story and turned it around either intentionally or unintentionally.
Also you have missed to note that Josephus quotes James the brother of Jesus as the fellow who's brother Jesus was called the Messiah. Scholars dont negate this part as a forgery. So in advance you are saying that Josephus has contradicting accounts of the same person in two different books being the same man. If you are making him out to be so inaccurate and contradicting, why trust him at all? Why have you put your trust on Josephus just to date Mark?
Josephus wrote wars in the year 78 if I am not mistaken. This is 45 to 50 years after Jesus. One huge issue you should be considering is, did Josephus also get it absolutely wrong? Why does he contradict himself with two different accounts of this same character Jesus, once as brother of James, the Messiah, and then as a madman who was prophesying the war in the year 66, not 33? A man who was tortured but he kept his mouth shut, then the Romans released him "because he was a mad man" and then he dies because some stone hit his head. But then, Josephus accounts for I think more than 10 messiah characters and all of them killed by the romans for sedition. But this man Jesus he calls the messiah as called by people is sent Scott free, once he is brother of James, the messiah, another time he is son of ananias, once he is a handy man, and all other messiahs are killed, only this messiah is let loose "just because he was a mere prophesying about the destruction of Jerusalem". Do you think people will call him the messiah for that only? Nope. This is absurd.
Read Josephus. All the people he quotes as Messiahs etc were rebels, revolutionaries, criminals who Rome killed for sedition.
This is the problem with hell bent mythicists.
They miss the historical method, though they boast it.
Anyway, it could be true that Mark was written later. If you are looking at possibilities, there could be many many possibilities.
When do you think Josephus places James, the brother of Jesus? Have you thought about it?