The Ecclesiology of the Catholic Church sees only two institutions as definitive by Divine Institution: the Universal Church, in communion with the Roman Church; and the local Particular Church, in communion with its Bishop. These are in fact, theologically if not geographically, the same thing; the Universal Church is manifested and made present in the Particular Church. The phrase 'local Church' does not mean a quasi-National 'church', such as "the English Church", which is an aggregation of dioceses. That phrase itself is common, useful, but imprecise slang. There is the Universal Church and there is the Diocese of Portsmouth.
Groupings of Particular Churches, as Vatican II taught, may for practical and prudential reasons be highly valuable or of venerable antiquity, such as the Patriarchates. But they are not by Divine Law essential. See Communionis notio AAS 85 (1992).
This is why our Holy Mother the Church has been circumspect with regard to Episcopal Conferences. In Apostolos suos she allowed Conferences to have a doctrinal competence, but only if (1) the vote is unanimous (in which case the teaching is the teaching of each individual bishop) or (2) where the vote is not unanimous but is confirmed by the Holy See (in which case the teaching is that of the Universal Church). She is apprehensive about the weakening of the Magisterium of the Bishop in his own Particular Church (i.e. diocese), and the influence of bureaucracies.
The duty of a local bishop is to ask himself whether a particular idea is in accordance with what has been handed down to him by his predecessors in his See and coheres with the Magisterium of the Church. It is not to ask "Is this a brilliant idea of an amazingly fantastic theologian?", or "Is this roughly in line with what my colleagues bishops X, Y, and Z thought last time we had a chat about it?", or "Can I really go against this when the the Episcopal Conference's ABCDEF Commission has considered it long and hard and come to a definite conclusion expressed in a big Document impressively supported by innumerable footnotes?"
There is a real risk that "autonomy and doctrinal Competence for Episcopal Conferences" may be the next major error to assault the whole State of Christ's Church Militant here in Earth. It is the very self-same principle which has corrupted and destroyed the Anglican Communion. It is a Diabolical threat with which those of us with 'Anglican Previous' lived and suffered for decades. Believe me, we know all about it. This is a problem which matters. It is most clearly a strategy elaborated at the very depths of the Lowerarchy.
Here are some recent remarks, very revealing, from a German bishop, Bishop Voderholzer of Regensburg, who seems to have his head screwed on the right way. He speaks of a document of the German Episcopal Conference which
"was released in the name of the Conference of Bishops, of which I am a member, without my having seen its contents, much less having approved it". He goes on to speak of his having "accepted the torch of belief and pastoral responsibility from his forerunners, including S Wolfgang." (In other words, not from Cardinal Marx or the Episcopal Conference. A Bishop and his diocese are not a department of a National Organisation.)
Exactly. S Irenaeus would have shaken Bishop V warmly by the hand.
Provincial Autonomy (the crisp title by which all this unpleasant stuff is known among Anglicans) is perfectly designed to become a forum within which innovating and unscrupulous bullies will be endowed with the procedural and personal mechanisms to subjugate an orthodox Bishop. And this is not just a problem about bullies: do not underestimate the danger that good and orthodox men might be worn down by a sense that they have a duty of solidarity with their episcopal colleagues. In English English, we call this "clubbing somebody". I am not sure whether this means 'hitting them with a big stick' or 'making them feel warm and comfortable members of a cosy club whose consensus they dread to break'. The practical consequences are much the same.
An earlier post touching upon Conferences is repeated immediately under this one.