I understand what you are trying to say Jav, but truly, I do not see the point, so let me get this straight:
Old rules:
Racer Vs
Racer: 7 single races <---------- (If they really want to)
Zoner Vs
Zoner: 6 zone battles and 1 single race <---------- (Again, if they really want to)
Racer Vs
Zoner: 4 single races and 3 zone battles
Your rules:
Racer Vs
Racer: 5 single races and 2 zone battles <---------- (If these guys want to play 7 single races, why shouldn't they be able to?)
Zoner Vs
Zoner: 3 single races and 4 zone battles <---------- (If these guys want to play 6 zone battles and 1 single race, why shouldn't they be able to?)
Racer Vs
Zoner: 4 single races and 3 zone battles <---------- (See any similarity with the old rules?)
If I understood your rules correctly, this is what I get.
As I said, I understand what you are trying to do, but it just doesn't work for me. The result of doing it your way would simply be; to force diversity into other peoples games, when they can have more fun by deciding what to play themselves.
Only good thing I see from it, is that the racers would get some much needed zone battle practice.
Just my 5 cents.