Do you feel aggressive margins are more important or aggressive ratios?
One problem I have is let's say a player is very aggressive as for example Rod Laver. Laver faces a ball machine like Bjorn Borg, well Laver is probably going to hit less winners and make more errors. Obviously the surface has to be taken into account.
I think from some of your examples that is why I believe Federer is so rarely upset by players outside of the top few His forehand is almost the equivalent of a powerful volley putaway by today's standards. When he gets a short ball it is rare players outside of Nadal, Djokovic and Murray that they had a chance to win the point. Just a theory but a theory from observation.
Nadal, Murray and Djokovic don't have the same type of putaway forehand that I believe Federer has.
Over the course of a year or a few years, if all the matches were charted I can easily see this as a super valuable statistic. Great job.