That probably is not what Nicea meant by "One Holy Catholic and Apostolic Church."
Also, the issue of being a elder is a red-herring. Church government belongs to this age, and is destined to perish with use. But the Eucharistic assembly is preserved. And equality does not refer to some interior unity, but to the Sacramental unity. In that passage from Galatians, St. Paul is explicitly drawing a parallel between circumcision which divided between Jew and God-fearer, and divided among the Jews between male and female; and Baptism, which is common to all worshipers of Christ. "As many as have been baptized into Christ have put on Christ." Immediately follows (or precedes) that passage, and the passage is in Galatians, which is all about circumcision. There is no restriction between male and female, between Jew and Greek. All are baptized, and all receive communion. All have been sprinkled with the Blood of the New Covenant, which in Hebrews is very clearly the Eucharistic cup.
This issue is precisely the division between the Protestants and Catholics, for the Catholics maintained that the priest receives the Eucharist on behalf of the laity, and withheld the cup from the laity. If our unity is invisible, and not in the Mystic Supper--using the term as de Lubac does--the whole split with Rome is superfluous.