In terms of the New Testament - There’s a few writers who based their stories off Macion’s Evangelion. And then some more who just made shit up for the sport of Apologetics. After that there were hundreds of scribes who poorly translated and changed the text, either by accident or on purpose.

I haven’t seen the Stylometry of the old testiment, but I’m guessing it’s almost all stolen from other regious texts. Genisis alone has two competing creation stories.

80+ authors is what I’m assuming.