I am just finishing an article in Spanish on the issue of how the Society relies in the NT canon. I have shown how the Society depends on early "apostates" to "confirm" the authenticity of the NT books. For instance, The Society quotes the "Athanasius canon of the IV century". But, was not him the champion of the Nicaea's word "homoousius", which equals the Son with the Father?........Also, interestingly, the Society quotes Saint Jerome to "show" that the Gospel of Matthew was written in Hebrew, and this is its argument to defend the inclusion of the Tetragramaton in the NT of the NWT. But, contradictorily, the Society accused negatively the church father Papias for using a non canonical book, The Gospel of the Hebrews. This shows that the Watchtower writer ignored that the Gospel of the Hebrews was that "version" of Matthew, which was considered "the original one", by many, as reported by Jerome. Furthermore, many of the quotations from that version, shows that it differs from the Greek version of Mathew which now many scholars now that it was not written by Matthew. So, if the Society holds that the original of Matthew was that which Jerome knew, the Society would have to admit that Jehovah preserved a forgery instead of the "original one".
For instance, The Gospel of the Hebrews uses the Hebrew version of Hosea 11:1 as the Gospel of Matthew does, but I strongly doubt that the Gospel of the Hebrews could use Isaiah 7:14 (in Hebrew) so as to show that Emanuel would born of a virgin.