Paul, a Jew who changed his name to Saul, a pagan name, founded the Church that decades later began to call itself the "Christian" Church. That's not a "mythicist" scenario. It's true. Is that the scenario you'd accept? It fits your narrative as being "worth considering".

There are NO original documents to examine; most were lost to age and decay and hundreds were destroyed in roughly the early 4th century because they didn't mesh with the claims made by Paul's pagan Church. So, there are copies of copies of copies of copies of the original writings and translation into other languages certainly changed much of what the orally passed along stories said.