The scholar Dennis MacDonald is all over that question of mimesis, so you can see him for details. It's just a question of comparing Mark's Jewish version of the dying and rising savior god mytheme, with the Greco-Roman, more Homeric versions. Mark's was properly Jewish, as in implicitly satirical since the hero here was surprisingly vanquished by Rome, just as the Jewish people suffered numerous humiliating occupations.

I don't subscribe to the Roman conspiracy theory. It isn't needed since the truth comes to the same thing: early Christians self-censored their message, distancing themselves from subversive Judaism after the Jewish-Roman War, to appeal to Romans.