OK, I'm being absolutely honest, here. I'm not a professional scholar by any means. I'm an atheist, bur was sent in childhood to Sunday School where my flypaper mind picked up a good deal of Biblical knowledge. I've spent the bulk of my life doing very ordinary things. But I have read a good deal, and some of it was odd stuff: 'Many a quaint and curious volume of forgotten lore'. As well as the key texts of major religions, I've read Theosophic and Gnostic works, studies of mythology, modern paganism and a good deal more. I recall the original 'Chronicle' TV documentary about Rennes-le-Chateau and did read 'The Holy Blood and the Holy Grail', about which I had severe doubts from the start, only to have them confirmed by the revelation of the 'Priory of Sion' as a hoax. That said, the idea that Jesus had a family was and is an eminently sensible one, if only because the majority of people do marry and have families.
I digress. What I am trying to say is that , to someone like me, there are a number of possible scenarios available regarding Jesus. They range from his being an outright myth to one of several people whose ideas and identites were conflated to produce an emblematic figure used as the centre of a mystery cult. There is no way, at this distance in time, of ascertaining the truth without a TARDIS.
For me, the two-Jesus idea is one that arises out of the differences between Nativity stories in Matthew and Luke, the odd coincidence of two men called Jesus being in trouble in Jerusalem at the same time and the various things I'd read and heard about the Roman Empire, Jewish customs and the situation of 1st Century Palestine. I write stories, and the idea appealed to me as much for its potential as a plot as possible history. That said, I cannot honestly say that I didn't read the idea somewhere else many years ago and forgot where. All I'm sure of is that in reading the debate Mr Pemberton refers to, the idea came to me and I advanced it as a possible scenario, but was insufficiently clear in my original post that this is what I was doing.
Let me be clear; I place no greater credence in this scenario than I do in any other of those available. We simply do not know precisely what happened, precisely when, and to precisely whom. But that particular one would make a rattling good yarn if anyone with the requisite talent were to take it up.
That said, I do intend to look at Szekelys' work.
Apologies for the length of this comment, but I felt it was important to make my position clear. I'm not the sharpest knife in the drawer and sometimes I don't make myself clear enough!