In keeping with the ambition of the OP it seems to me at least that it is reasonable to assert a claim that the early church fathers themselves provided the teachings which eventually gave rise to direct RCC heresies, if in fact we can demonstrate it rationally. Unfortunately simply saying it doesn't prove anything. Even if this claim were precisely true, unless you intend to be a traditional Roman Catholic, placing more importance on the writing of the early church fathers than is necessary, reading them will not of itself produce a Roman Catholic.
If we are seeking to establish the origins and development of the RCC, as we know it today, then it isn't surprising that those responsible for the implementation of specific heresies looked to the Church Fathers for their justification. Where else would they look. They could scarcely look to the Qur'an could they? Yet unless you can read Greek or Latin you can only take another's word that the basis for all present RCC heresy can be found in the writing of the early church fathers.
It seems that some would suggest that the way round this problem is to be equipped with discernment. I have to say that truth cannot be discerned. Only error can be discerned. Truth must be taught it cannot be discerned. If by discernment we really mean communion with God, then none need to be taught, who have true communion with God. In that sense anyone of us could come to a right and true understanding without so much as opening the page of a single book. But if what we mean is really discernment, then we are speaking about a function of the mind in submission to both the Spirit and to true knowledge. Intuition on the other hand arises out of the mind and has to do with understanding born indirectly from prior knowledge.
The whole benefit and meaning of the apostles who precede the early church fathers, is that they were taught of Christ Himself. The Lord said that he would send the Holy Spirit and that He (The Holy Spirit) would remind them of that which He (Christ) had taught them. In this sense we have the Scriptures which are reliable because they are based on the testimony of men who knew Christ. We also read that before Paul set about his ministry he went to the apostles and tested his understanding to make sure that it conformed to the other apostles yet Paul also received his understanding directly from Christ Himself. So even in Paul's case, who was not with Christ, his words were tested by those who were with Christ.
None of this has anything to do with discernment however, and to confuse the two, as though discernment is a teacher, is a false premise altogether. Discernment is not a teacher. The Holy Spirit is the One who leads men into all truth, and the Scripture is the word by which we know what Christ said according to the Apostles. If reading the Scriptures and deriving a full and complete understanding on the RCC was as simple a matter as some suggest then there could be no possible division in understanding between any christian. Yet the church is riddled with division and the basis of all of these divisions is doctrine. Even if you took the reformed churches you will find there are thousands of divisions all based on some doctrine or other.
If we insist on blaming the church fathers for these divisions then we would have to read them throughly to know if there is any merit to the claim. Or at least where the merit may be both in saying it and where it can be found. Unfortunately it is not possible to discern the church fathers unless you have the living word dwelling in you richly and communion with God. Discernment, nor intuition will reveal truth unless you have communion in the spirit with God who is Spirit. Otherwise we will very likely find that what we discern will prove to be misleading, or else our intuition will prove to be a poor guide.
The words of the church fathers are not canonical nor are they living words in the way the Scriptures are invested with the power of God unto salvation. So in the end if what we are left with is the Scriptures, which we take to be the living word of God, able to save, correct, instruct, train in righteousness and so on, we would have to ask can the heresies of the RCC be properly and fully discerned as some say by reading and knowing the Scriptures? After all if we are seeking to determine that the errors of Rome can be discerned by no other instrument than the Scriptures, then the Scriptures themselves would have to explicitly give instructions on the precise heresies which constitute the heresies of Rome. Either that or else the Scriptures would have to lay open before our eyes such a plain teaching in all things which address RCC heresies that they can thereafter be seen to be heresies by a pure rational means. If we do not know these things ourselves and cannot lay them out before other men ourselves, then on what basis can we say that the Scriptures has a corresponding truth to every heresy of Rome?
I believe, that in the Church fathers writings, can be found the whole of the Scriptures written out with the exception of thirteen verses. Imagine that for a moment. These men wrote out between them almost the whole of the Scriptures in there dissertations. If every single Bible were destroyed in the whole world, their writings alone would preserve all bar thirteen verses.
I am not so certain that we can be so flippant in the way we dismiss their writings. I do not personally believe in reading them as though to follow their lead or even to substitute the word of God. I do read them to make a careful study of how error came into the church and to test whether the claims that all the Roman doctrines can be found in their pages. It is a curious fact however that the overwhelming number of Roman Doctrines which are called heresy did not appear until the 11th Century as formal doctrines of Rome.
The Rosary, Indulgences, repetitive prayer, the mass, confession of sins to a priest, adoration of the wafer, forbidding the scriptures, all came into practise in the 11-13 century. Purgatory, introduction of seven sacraments, the Ave Maria, the immaculate conception of Mary all came into practise and cannon between the 13-15 century. The doctrinal basis for many of these practises can be found in earlier Catholic teachings, but the practise and embrace of these doctrines was by no means truly Catholic. Purgatory can be found presented by Gregory at the end of the 6th century, yet It didn't become fully enforced as a truly Catholic doctrine until the 13th century. Papal Infallibility was first officiated into church cannon in 1870 yet the most powerful pope of all time was Innocent III in the 13th century. Where did his power lay? It was not in a claim to infallibility, it was his political standing and ability to directly set one prince against another and thus to subject to himself the greatest influence the RCC church has ever known both before or since.
Therein lies the complexity of the RCC. It finds its origins in a political relationship with the Western Empire of Rome through Constantine, and at that time the Catholic Church adopts many Roman, and therefore Pagan ideological precepts and teachings at its political heart. Yet these Pagan ideas are themselves grounded in Greek philosophical thinking.
I have asked myself the question many times why it was that in the 10-13th centuries the peculiar church which we now call the RCC came into being in the way it has done with its now familiar heresies. My thought is that it actually has more to do with ancient Greek thinking than it has to do with Roman political reality. The Greek philosophers with their Pagan embrace had more influence on the Church between the 11th and 13th Century than it had in the first three centuries of the Greek Fathers. This is because they actually understood these philosophies in the context of their direct influence and rejected them out of hand. If you study Justin Martyr and his discourse with Trypho he brings this point out very well. He doesn't condemn philosophy he simply recognises its futility in producing a true revelation of God. Yet he also acknowledges that, as in his own case before he was converted, Plato is very powerful and influential.
In the first renaissance in Europe which was driven and controlled by the Church with the development of Cathedral colleges and the expansion of scientific knowledge as well as the incorporation of eastern thinking via Byzantine, which itself was preserved in Arabic and Islamic culture and development, Rome took on a much more Greek rational line of thinking and the works of Latin Fathers such as Augustine took on much more meaning and recognition. In short the RCC has more than anything else provided the framework of neoplatonic philosophical thought giving rise to individualism and self benefit, though benefited by membership rather than by autonomous pursuits. The effect was the so-called enlightenment of Europe, yet this has in the end only led to the same Greek belief in a philosophical logos of the transcendental man reaching his own full potential of self realisation and self purpose. Today it has become relativism both in the world and increasingly in the church as well.
To argue that the RCC is somehow divorced from the ancient world therefore and stands in a unique position with regard to it's understanding as well as its doctrinal expressions and developments, is almost akin to agreeing with Rome itself. It is like saying that Rome is actually the true expression of the body of Christ on the earth. In such a position it is not difficult to move into the idea that its bishop is therefore the true expression of Christ Himself. Yet I know in my conscience that Rome is in reality a means to an end and not the end itself. Its uniqueness may well be partially irresistible, but it is only unique because it is foretold as being a mother of influence with many children, and not because it is an end in itself. Rome is not the finality of this age. The finality of this age rests with Israel which is the only truly unique people and influence in the world by God's choosing. Therefore I cannot see Rome as being the concluding reality. In fact if we look at Revelation the woman who rides the beast is herself devoured.
I believe that to look into the church fathers therefore requires in the first instance a division between the greek fathers and the latin fathers. Thereafter in reading the latin fathers we can more easily see where the philosophical bedrock of modernity was laid and why the present day Rome with its ecumenical powers of influence may prove to be that influence and not the ambition which it has given rise to. In that mind of thinking we may see Rome as less a matter of people, and more a matter of a system of wickedness rooted and grounded in Satanic ambition. Perhaps we may even be able to truly see its members as men and women in need of respect first of all because many have given up the universal right of individualism which this age has brought to bear, and have embraced the benefit of communion. This is a far better thing that anything the world has to offer, yet we will so easily embrace the world with its temptations and ambitions to make every man a god, and reject the people of Rome who are willing to be constrained by decency and community of purpose.
I don't say that this is of itself my ambition, but it does help me to see men and women and not false doctrines and heresies which have been pressed upon them by a working of Satan spanning more that 3500 years. We are told in the Scripture that those who make a sacrifice but neglect mercy have not seen the hand of God. I prefer mercy every time because it is God Himself who saves men and those who know His name cannot be the least to be saved if they call upon Him. Nor can Roman Catholics be rejected if their faith is truly in Christ. If we get to separating history into those we imagine were saved from those who we imagine were not, on the basis of perceived or real heresies then we will find that the overwhelming majority of those who take the name of Christ in the last 2000 years have perished because few of them had any say in their knowledge of Christ but were overwhelmingly subject to those who were over them in Christ.
