You seem to ask two different questions. I’ll answer the one inside the message body.

My suspicion is that the Jesus movement — when it was still a Jewish apocalyptic sect — is perhaps a century older than the Christian gospels place it.

I think there’s good evidence that the early Jesus movement identified its patron as the Jesus mentioned in oral history, and later the redacted Talmud. The upstart mission was to bring a comfortable middle ground clarity to common Jews who were being pulled in numerous directions by Sadducees (Zadokim), Kararites, and Pharisees at a time where halachic guidance was centered in Babylon, not Jerusalem. Like almost all efforts of playing peacemaker in hostile circumstances, the idea never really gained traction. Whomever it was they identified by the name later come to be known as “Jesus”, this Jesus wouldn’t have recognized very much being done as a movement they were alleged to have started.

I believe normative Christianity (gentile-based Christianity) is an adaptation of what could be best called Paulianism as ingredients of a much larger Greco-Roman soup based on anti-Jewish polemics almost two centuries later when Christianity finally became its own seperate religion after there were no Jews to object with a different recollection. The same Jesus who wouldn’t have recognized the acts of the Apostolic period would have likewise been baffled by this too.

Another century later, the flagging Roman Empire under Constantine running almost completely out of gas adopted codified Christianity (backdated by committee and it’s canon heavily editorialized by the early literary ‘Saints’, elevating Jesus to god Himself) as it’s empirical religion to replace vassal state tribute in the form of individual tithing amongst the empire’s citizenry. At this point, the Jesus movement moved so far away from its classic origin that it is like comparing a hot dog to a submarine.