I’ve read that the British actually often do say “Two Corinthians” (though I haven’t verified that for certain), and I’ve heard a devout Christian from New England do that too. Trump’s mother was, of course, British. I think you are just displaying a cultural bias on this subject. You just think that your way is the only “right” way.
CAVEAT EMPTOR .... you’re buying “as is” .... and there will be no do-overs!