I watched a HS player who was pretty dominate based on the late swings. I have no idea how hard he was throwing this day, but he is on record with a 86mph FB. Playing a good team and ALL the batters had trouble catching up to the FB and they LOOKED over matched more often than not.
Opposing pitcher was throwing no where near as hard and was just as affective. BUT the difference was the batters didn't LOOK like they were getting dominated even though the number line was pretty darn close.
Even though the outcome may be the same, the perspective of an observer would state that the pitcher throwing hard was better.