Ferrer has beaten Djokovic twice on clay in 04, 07, and 09 when Nole wasn't the player he is now on that surface. That he beats guys like Almagro is not surprising because he is just a better overall player.
Simon is better on hard but today in isolation, he hit the ball much harder than he usually does.
You're making no sense. You said the only player Ferrer beats is Murray.
But he has beaten Djokovic 3-1 on clay with one tight 3 set loss in Djokovic's best season. Ferrer pushes Nadal hard, beats Murray and Del Po regularly and cleans up with anyone else on clay and yet you don't think he's better equipped for the surface than Simon?
Ferrer loses to Nadal on clay. Check out to whom Simon loses more often than not.