August, very good summation!
I have a few things I disagree with/would like to hear your opinion about.
First, while Novak isn't as aggressive as federer, he plays much closer to the baseline than Andy. He also has a much better serve, so while on Fed's service games, it is on his racket, the same could be said for Novak when he is serving. Also Novak will definitely play a more aggressive style against Fed than Murray.
Given current form, I am not comfortable saying it is on anybody's rackets. More so than against Andy, I see this early on being decided by tie-breakers instead of Roger just being able to rely on this serve, then waiting for a good opportunity in Andy's service games. Novak will not give nearly as many opportunities on his own serve.
In short, while Novak plays a lot of defense, he is not a pure defense player in the way Andy is and will be more comfortable countering Fed's offense with his own.