Ofcourse you won't be able to cross compare exact statistics from every zone but if you theoretically calculate a number which gives your "value" in the zone. As long as you know the range of this number of each zone, you can compare it to other zones. For example, In flagging zones you calculate a number from the flagpoints and the number of kills which gives a number from 0 to 1.000.000. In balling zones you calculate a number from the killpoints and whatever to get a number from 0 to 1000. All you need to do is to get these both numbers into the same range to be compared. Hm I guess such calculations can be really difficult and quite unreliable.