Seems like a fair summation to me.The Christian scriptures say some things about Jesus that can't be true because they are impossible. But they also relate things that are perfectly possible, and some of them are inconvenient for the miraculous Jesus. Like his mother thought he was nuts, or that he had brothers called James, Joses, Simeon and Judas; and "sisters" too, plural and unnamed.
These things are not consistent with his mother being a virgin told she was giving birth to the Son of God. The Son of God is insane? The Son of God has at least six siblings? So the Biblical Jesus is a composite character with possibly true and certainly false incidents in his career. Based on one real or imaginary person? Or more than one? We don't know, but we do know that there is no single "Biblical" Jesus, except in the minds of literalist Christians.
More importantly, if Mary thought Jesus was crazy, was she suffering from amnesia? Wasn't she visited by an Angel and a bunch of wise men in her youth telling her Jesus was the Messiah?
Personally, I think we can't ever really know but it does seem to me that the most parsimonious explanation is that the Story is wild exaggeration of the life of one or more real people. Get rid of the supernatural crap and the story just isn't that special or unlikely. A wondering preacher in the middle east irritated the Romans and the local elites and was killed for it.