That’s all you have to say?
Asking for chapter and verse? If you are going somewhere with that line of questioning, don’t be coy.
I think I know where it’s going. How about checking the cited sources at the link provided? The specific answers you seek are likely to have been touched upon at those sources.
Read a great deal of it. The narrative presented does not support the conclusion drawn. The author admits as much when he says that it is simply a tenet of faith that one believes in the overarching providence of God as ratifying the canon. That's fine, but it's like
Q: Why is the sky blue?
A. Because God made it that way.
That's true as far as it goes. But, we can go farther, using the reason endowed minds give us by God.
The Church Fathers who defended orthodoxy and refuted heresy always found orthodoxy in what had always been believed by those to whom the were joined. One and only one quote from Gregory of Nyssa in his refutation of Eunomius, who persisted in the Arian heresy
I may be counted among the least of those who are enlisted in the Church of God, but still I am not too weak to stand out as her champion against one who has broken with that Church. The very smallest member of a vigorous body would, by virtue of the unity of its life with the whole, be found stronger than one that had been cut away and was dying, however large the latter and small the former.
Though I have not read Eunomius, I would not be surprised to find out that he claimed to be led by the Holy Spirit and that he also was in concert with the mind of the church.
But, 1600 years later, it is St Gregory and his teaching which is held as orthodox - and that consciously by the Orthodox and Catholic traditions. The way Protestants handle the Fathers is always a mystery to me.
I realize that I wandered off the specific topic of the canon of scripture. Suffice it to say, the very same Church of God to which Gregory was joined, would have seen the absolute necessity of defining what it was and what it was not.