Personally I don't know if it is good idea or no.
It is true about "global statistics are falsified", for exemple I played 1000+ hours in alien invasion )
The problem is : players play for stats and no fun if there is "ranked" tag.
I stay neutral )
Hmm, it is possible to count only kill and death by others players and no aliens ?
For example if you kill/die (by) alien, your stats don't change, but if you kill player, your stats are changed.