@Don
But my point is that a possible starting point by scholars cannot be (as SA puts it in the OP) "unhistorical or fiction" until the consensus about Paul and James is addressed. THAT's the starting point for scholars AFAICS.
Maybe we agree somewhat but words are getting in the way.
What I got from the OP was that SA thinks there is a spectrum of possible relationships between Jesus and the gospels (say gMark for specificity). something like:
Eyewitness.........Based on......Outright fiction
|E|.....................|B|..................|F|
with recognition that between B and F there are many ways for a character to be based upon a real person, and many possible degrees of dependence.
If I have correctly understood SA's teaching, then that full spectrum would be a natural "starting point," since it is simply a ground fact about how characters who appear in literary works in general might be influenced by specific real people in general. The example "
Godfather singer character & Frank Sinatra" would fall somewhere between points B and F. Lincoln in
Abraham Lincoln, Vampire Hunter would be very close to point B.
Anything contributed by scholars would occur downstream of laying out the spectrum. Even granting "summary judgment" (accepting
arguendo that Jesus was a real person, Paul wrote about meeting his brother, and Josephus wrote about that same brother being tried in 62 CE), that would only compel Jesus & gMark's relationship to fall somewhere strictly to the left of point F,
not exclusively somewhere between B and E, but anywhere except point F.
So, SA may sensibly inquire, what happened to the entire stretch between B and F; why only between B and E?
Anyway, that's how I understood him, and what I think the force behind his question would be, all the more urgent when summary judgment isn't granted.