Re: Being aggressive doesnt necessarily mean hitting more winners than your rival
I think it's important to take forced errors into account.
In my opinion, they are just as valid to count as winners.
If you have a player who lacks firepower, but can still force errors, he should be though of as offensive.
A player who forces 50 forced errors in a match should be viewed as more offensive than somebody who makes 25 winners.
I also agree with the OP. You see this especially when a match has a serve&volley player on one side of the net. He is by definition the more offensive player, but will end up with less winners as he is passed numerous times. I imagine a match like Stepanek vs. Djokovic would result in many more winners for Djokovic despite him being the far more defensive player.
__________________Nadal Gulbis Ferrer Wawrinka Baker
Isner Dimitrov Djokovic Querrey Tsonga Gasquet Nishikori
Seppi Harrison Russell DelPo Benneteau Baghdatis Anderson Berankis Murray
Berdych Monaco Granollers Bellucci Troicki Roger-Vasselin Lu Verdasco Paire
PAW Titles: Brisbane 2012 & 2014