I'm not totally convinced by this. Some of the animal archetypes predate the medieval bestiary and appear in, say, Roman or Greek plays, or pre-medieval texts like the Talmud, or Aesop's Fables. EG Crocodile tears goes back to Plutarch. Lions' association with Kingship is Biblical.
There also seems to be little mention of Norse Pagan influences despite animals (both mythical and mundane) being prevalent in Norse mythology.