No, I haven't heard that story before, but I can picture the scenario 😂
What I do know is that it is suicide to bring a huge horse into battle against a small/medium, swift horse. At least close combat.
Medium small horses are the best, and the head of the knight on the huge horse will hit the ground before the huge horse has even managed to turn it's huge body
Sorry for the slightly macabre picture.
The medium horses are the gymnasts of the horse world, and the huge ones are the slow but strong muscle
Not unlike most other species.
Both important, but for different purposes.
An archaeologist that spesialize in horse armour! How cool is that?!