Winning Queens and playing 2 Wimbledon finals as well
Irrelevant to your point. You questioned Murray's ability on grass because he only beat Tipsy in a close match. We're simply pointing out the flaw in your logic, given that Nadal was run close by a player who inferior to Tipsarevic.
The top players don't always destroy opponents, particularly guys who can play as well as Tipsarevic can. I'm sure Djokovic and Federer would tell you the same thing.