That's an ad hominem argument. If I did that, the RM would immediately chastise me for reading your mind.
Clement's "Epistle to the Corinthians", Irenaeus' "Against Heresies", and Cyprian of Carthage's "On the Unity of the Catholic Church" are all available on the Internet, and are not "unsupported declaratives".
The are as "extra-Biblical" as this article is.