The Fathers play a role only in their consensus, not individually. That to which the Father consented is what the Church considers the correct doctrine.
This was my understanding, and when you all quote the Fathers to me in support of a point I have been assuming that the quote is in agreement with an approved position of the Church. Should I not do that? :)
I believe we usually quote the Fathers on things that are either dogma or doctrine of the Church. I believe we would use the Ecumenical Councils, but not local councils, in the same vain.
Yet, individual Fathers can always say things that are not doctrinal or dogmatic, but are presenting hypotheses (theologoumenna), religious opinions, instead. It is important to state that this is so, lest it be misconstrued as the teaching of the Church.
All Fathers has such opinions. Thsi is best made clear when it comes to such topics as Christian canon. Much disagreement there. St. Gregfory of Nyssa believed in universal salvation (he picked that up from Origen). St. Augustine believed the Jews were descendants of Cain.
Individual clergymen who advanced opinions to the level of doctrine or even dogma were challenged by Ecumenical and local councils. as long as they did not challenge dogma or doctrine, and deferred to the Church, their opinions were simply that, their opinions. One must be careful not to present their opinions as if they were dogma/doctrine.