Maybe later
war
but everytime I go
to MW or EW, no
ones
fighting
and
the lpeepsnare
justb rolling the map 
...Or people are milkrunning/shade vulching. By making perks arena specific, it would force those guys into the arena they want them for. No more earning many perks in the unpopulated EW/MW arena, then bringing them in for perk planes in the LW. If you want to use them in LW, you earn them in LW. People would still do it, but they'd have more of a chance to encounter resistance.
Wiley.