No, Paul doesn't oversimply much, but he wrote before there was such a thing as organized Christianity. My thesis is specifically about the established, Catholic Church.

Mind you, Paul implicitly assumes the Gnostic distinction between inner and outer interpretations (esoteric and exoteric, for "spiritual" or "natural" listeners). That distinction implies disneyfication or oversimplification for the initiates who aren't ready for the deeper message. "He who has ears, let him hear." Jesus taught in parables that contained hidden messages within a simple-sounding story. These parables were allegorical.

We shouldn't think of the ancient Jews so monolithically. In the Hellenistic period, Jews merged with Greek society, to the chagrin of some conservative Jews. Jews have always argued with each other about these things (Pharisees, Sadducees, Essenes, etc), just as there are differences within practically any group. Some Jews thought they should fight physically against Rome. Others admired Greco-Roman philosophy and wanted to combine it with Jewish tradition. Christianity broke off from Judaism because of that difference of opinion.