That's the benefit of being at the Top, you can't play against the best opponents until QF or SF
Ranking isn't everything because a player can be high ranked with a lot of luck. Berdych is an underrated player who would have knocked out any of other top eight seeds had he been in a different portion of the draw.
Nadal was lucky with first two round jokes though.
Mugdull's whole draw was a joke. Rochus, Karanusic, Hass, a tired Gonzalez, and Simon are not that hard to beat.