Yes, Jesus is the corresponding ransom for all. But the ransom is not the same thing as the mediator.
Moses was a mediator of the old covenant, between Jehovah and Israel.
Jesus is the mediator of the new covenant between Jehovah and Spiritual Israel.
Aaron was the priest offering the sacrifices that atone for all, Israelite and foreigner. And then there were the sacrifices.
Jesus is the high priest offering the sacrifices for Spiritual Israel and the non-spiritual Israelites.
Jesus is the sacrifice or ransom that atones for all.