It's also possible that the stories were an amalgamation of several itinerant preachers. It might explain some of the conflicts between different gospels. But that there were real people at the basis of these stories is a pretty mundane claim, and so the mundane parts of the story i'm willing accept without much evidence. That a preacher had followers, gave sermons, pissed off the wrong people and got crucified is pretty mundane for the time, i'm willing to accept that those things are likely true.