Now that I reread your post. I think this is what you wanted me to address.
It would still be the same problem, right?
Orthodox say that they are the true Catholic Church.
Yes, we Orthodox do consider ourselves truly catholic. This is, in part, why we call the Roman Church just that, or the Roman Catholic Church and not plainly the Catholic Church. Likewise, we call ourselves Eastern Orthodox, not because we aren’t catholic, but because it differentiates us from the Eastern Churches that aren’t Orthodox (i.e. the Nestorians, yes, they still exist after all these years).
The ECF’s used both Orthodox and Catholic in order to describe themselves. But just because one used the word Catholic doesn’t make them Roman Catholic, at least, according to Eastern Orthodox Christians (and even some Protestants).
It would be silly to assume, as has been mentioned above, that just because we don’t call ourselves the Orthodox Catholic Church all the time (we do call ourselves that frequently, from what I’ve read) that we somehow reject catholicity. We would actually refer to ourselves as just Christians, which we are. But because of the multitude of of schisms and denominations out there, certain titles catch on in order to differentiate one from the other. It just so happens that we got slapped with Eastern Orthodox. Again, we aren’t denying that we aren’t truly catholic. The word ‘catholic’ means not universal but fullness and we believe that we have the fullness of the faith.
I hope those two links aren’t taken seriously as denying our own catholicity. Any Orthodox Christian worth his weight in salt isn’t going to deny that we are catholic without simultaneously leaving the Church to find true catholicity. Does any Christian (Prot/Cath/Orth) out their think they aren’t catholic (again, here meaning fullness)? I doubt it.