People who like Lemon Drizzle cake too much are also at an advantage when it's windy because they don't get blown around as much
I think you do a sterling job Si and I don't think it's at all fair to ask you to do more than you already do.
The grading list isn't a competition (there's no trophies for it), it's whole purpose is to try to predict how well someone is going to shoot over the next season.
I suppose you could liken it to trying to predict a horse race based on past form - there are far too many variables for any system to be able to predict it accurately. AM / PM Session is just one variable - there are plenty of other variables too.
However.. by and large the system we have in place at the moment works pretty well, yeah it doesn't always get it right (because that's not possible!) but by and large it does get the bandings about right.
If anyone thinks the grading system has put them in the wrong grade - there's a very simple fix, elect to shoot in the grade you think is fair. If you think the system has predicted that you'll do better than you actually will - practice more and knock more targets over.