[HoneyBadger]

Yes, but you see, that's not the answer, because that same tribal chief is going to use another "poor pony" to carry his armor, and quite possibly a sword-bearer to carry his weapons. The heavy black steel full plate is only going to be worn when battle is expected, or for the may day parade. The rest of the time, the chief's probably going to be wearing brigandine, or just riding leathers. He might wear heavy armor at home, and he might even wear it when he's sitting around the camp-fire or inspecting the troops, so you can shrug off assassination attempts, but he's not going to wear it on 75 mile rides, because that's how you lose ponies. The only time it MIGHT be worn on long rides is if the chief had 5 or 6 ponies and cound switch them out regularly every couple of miles.