[HoneyBadger]

He definitely did it in armor as far as I know, he was afraid of running into the enemy along the way, so he carried weapons and armor. And that's the thing about humans vs horses-humans can travel steadily and wear down a horse if the horse has to keep moving. Stopping and starting is fine for a horse, but a human hunter might not give the horse the option. That's also why wolves hunt in packs, because an individual wolf quickly gets tired, while a pack can relay off and give it's members time to recover in a long hunt.