I really don't see the point of this Galatian.
I could line up a series of historians against whatever list you wish. It would only prove we both have extensive resources.
the fact is that by the 3rd century there was no dispute of the 27 books. Even the Shephard of Hermas was off the list as a book of Scripture.
A devotional yes, Scripture, no.
As some one has already mentioned the Spirit of God bears witness to our spirits to those whom are His. This same Spirit superintended these historical events and knows which are His books as well as who are His children.
Someone else has noticed that several groups of opposing philosophies seem to be claiming this same Spirit.
Well, this was explained in Matthew Chapter 13. The object of the enemy in this chapter right off is The Word of God.
So it is no small leap of the imagination to see where the confusion is coming from.
However The Lord will prevail in the end and take care of it...
49 So shall it be at the end of the world: the angels shall come forth, and sever the wicked from among the just,
50 And shall cast them into the furnace of fire: there shall be wailing and gnashing of teeth.
51 Jesus saith unto them, Have ye understood all these things? They say unto him, Yea, Lord.
I guess I said all that to say this: God can and will use whatever or whoever He wishes to accomplish His will on earth. As many have said He used a donkey to speak His word. If He wishes to use the Church of Rome or any other Church of any age anywhere, then He can and will.
The Word of God says as much, concerning His enemies:
Revelation 17:17 For God hath put in their hearts to fulfil his will, and to agree, and give their kingdom unto the beast, until the words of God shall be fulfilled.
Yes, I may be the one who of those to whom this passage refers, but I don't think so.
HankD