You raise a good point, designs.
We who have been indoctrinated end up debating a matters that should be stripped down WAY further than we do.
Actually, it seems that the word "mediator" doesn't show up in the NT until long after Jesus was killed. And now we know that word carries a sort of legal/technical sense in discussions.
The gospel of Mary conveys a more ordinary sense of Jesus as a conductor to God. He showed the Way.
Talking to others who didn't know the way he said "no one comes to the Father except through me". Does that mean I must infer he is claiming "I am THE MEDIATOR".
Jesus may have come from "the Good" as the Mary Gospel says it. But the tricky doctrines and theologies we argue about may never ever have been in Jesus' heart, mind or teachings.