The question of who has what authority is a difficult one in both Eastern and Oriental Orthodoxy. Rome has a much clearer, and more Western legalistic, model.
In Orthodoxy there are, in practice, two forms of authority which might be called (to use Western legal terms) ?de jure? and ?de facto?.
Some authority derives from Canon Law. No-one has, for example, authority to change the dogmatic decrees of the Ecumenical Councils ? not even (assuming such a thing to be possible) a future Ecumenical Council. Ecumenical Councils had the authority to change to disciplinary decrees of the earlier Ecumenical Councils (and did so: the example of imposing a celibate episcopate is an obvious example) and of the Regional Councils and of the Fathers.
Patriarchs and bishops have authority to make disciplinary rules and decisions within their own jurisdictions, provided always that these conform to the Canons. This is what I would call ?de jure? (of right) authority.
However, especially in Oriental Orthodoxy, Patriarchs and, to a lesser extent, bishops exercise what can best be described as a ?de facto? (as a matter of fact) authority in that few people are likely to challenge their decisions, and there may be no effective means for doing so, even if the decisions appear to be contrary to higher canonical authority.
As an obvious example: in 1911, Pope Cyril V ordered the removal of the following books from the Old Testament Canon: Tobit, Judith, the Compliment of Esther, the Wisdom of Solomon, Ecclesiasticus, the Epistle of Jeremiah, Baruch, the Compliment of Daniel (Suzanna, and the Three Youths), and the Books of Maccabees. A further example: in 1971 Pope Shenouda III changed the Church?s rules regarding divorce and made adultery effectively the only acceptable ground, disallowing the other grounds which had previously been part of Coptic Canon Law, which had been incorporated into the Church?s rules in 1938 and into the Egyptian civil ?personal status? law applying to Copts in 1955. This has created a well-document ?divorce crisis? amongst Copts, especially in Egypt. Serious domestic violence, for example, is no longer a ground for divorce or, at least, a ground for divorce with the right to remarriage for the victim.
An added complication is the distinction between dogmatic and disciplinary decrees. I think the imposition of a celibate episcopate is a disciplinary matter. None but the most theologically illiterate Orthodox would argue that a married man cannot be a bishop rather than that church law does not allow it now.
The question that inspired your reflection on authority ? the ordination of women ? is obviously much more complex. Is the male-only Priesthood a matter of dogma or discipline? Could a future Ecumenical Council decree that women can be ordained?