Well, of course triads are popular, and patterns are commonly summarized by dividing them into three parts. That hardly means all triads and trinities are equivalent. BS aren't saying only that there are lots of triads out there. They're saying explicitly that lots of other writers agree with them even on these details. They're implying that all of those writers are on the same page with BS, so that if you agree with Lacan, Hegel, or Nietzsche, you ought to agree with BS.

You see this megalomania more clearly in the Syntheism book, which boasts repeatedly how important their worldview is to humanity. It's all bluster, though, as when they say often "of course" this or that is so, when they demonstrate nothing of the kind. They assert whatever they like because the literary tradition of Continental philosophy gives them that "artistic" license.