For a lot of You guys it makes sense, but not for me. The fact is, when a horse was hitted in battle, let's say by an arrow, it didn't slow down. It was running even faster, becase of the big adrenaline that wound gave it. Any additional wound was like an steroid. Of course, it didn't last long - the horse died in action, or just survived the battle and noticed, that it was hurt.
If You guys really want this game to be realistic in 100%, or close to that, Plated Chargers, horses with an armor of plates on it, or any at all, should be removed aswell. In medieval times horses weren't 'dressed' with armor - not even with, let's call it, a 'cloak' of cloth. Horses with heavy armor, or any at all, were used only in tournaments - just because it made them slow and un-manouverable.
So, in my opinion, it shouldn't be added to the game.
Greetings!
<it's a wall of text, so sorry in advance for any mistakes>