The premise of this thread is that the overriding element determining who wins is the guy who doesn't have to play 2 of the top 4 guys back to back.
This theory that having to face 2 of the top 4 instead of 1 makes all the difference while having some merit is not supported by lots of data, with the prime reason being that a lot of factors including the players own form on the day/the potential for an upset changing the shape of the draw etc.
We can never know what WOULD have happened if Djoker had to face Murray in the semis. What we do know though is that Djoker took out 2 of the top guys in a row at AO 11, USO 11 and AO 12 and at the WTF. Federer won Wimbledon having to beat Djokovic in the semis and then Murray in the final. At USO 2012 , Fed didn't even make it to the semis to be a factor. So really we are running on a sample size of ONE to prove this point.
ALL ELSE BEING EQUAL, yes you would much rather face Ferrer than Murray. But all else WILL NEVER BE EQUAL, is my point.