Exactly. An example from outside the Bible might be Achilles. There was probably a great warrior with that name in the Mycenaean Greek world. Later storytellers probably just added more to make it sound better or the material was from other warriors who were like Achilles.
Some of Jesus’ teachings definitely come from the milieu of the Roman era in Judea and Palestina.
Personally my favorite head canon is that Jesus was, or his parents were, Egyptian born Jews or Coptic converts to Judaism. It’s a reverse Obamas birth certificate. There is so much time spent establishing the lineage and explaining the flight to Egypt.
Assembled a thousand years after the fact by a group with a vested interest in solidifying the narrative to fit their own.
Hell, the Tanakh didn’t really get put together until well after Christianity appeared and it was a reaction to Christians appropriating Jewish literary culture to establish their own.
It’d be similar to people a thousand years from believing that Christian Gray is literally descended from Edward and Bella.