Your study was neither deep nor thorough, as far as I can see! At the Robber Council of Trent , which is classed as a Ecumenical Council, by Rome, and obligatory on all Ecclesiastics and on all ," who promise and swear that they will continue in obedience to the Church of Rome", it was firmly stated of the Scriptures ,'Nor, will I ever understand or interpret it, except according according to the unanimous consent of the holy Fathers."
Thinking on Matthew, there are different interpretations, Maldonatus a 16th Cent, Jesuit, whose Commentaries are mentioned as, 'the best ever published,' says clearly, ' There are amongst ancient authors some who interpret,'this rock, that is,'on this' faith,,or,'on this confession of faith, in which thouGr hast called Me the Son of the living God,' as Hilary and Gregory Nyssen, as well Chryostom and Cyril of Alexandria. S.Augustine going still father away from the true sense, interprets , on this rock, that is, 'on myself Christ, because Christ was the Rock.' Origin however, claims, 'on this rock, that is to say, on all men who have the same faith.'
Launoy, another Jesuit I understand, made lists,
17 Fathers in favour of the Rock being S.Peter.
Fourty Four, for is meaning the faith S.Peter Confessed.
Sixteen for it being Christ Our Saviour and eight for it being all the Apostles.
Archbishop Kenrick, in the famous speech never given at Vat.1 wrote,
'From this it follows either that no arguement at all or only a very feeble one , can be drawn in proof of the primacy of Peter from the words ,'on this rock will I build my Church.'
(Fred., Documents Vol1, pp195.)