IW really coulda put some more thought into Extinction, well actually not really. They could have copied BLOP2 in a few ways and give us Extinction Challenges every week that would have helped earn some CXP.
-most cryp kills
-most hives destroyed
We could earn more for playing Extinction with fellow clanners instead of randoms. They could even run these "mini" Extinction events during the off-week of clanwars so even if your clan is not all that good or simply doesn't stand a chance in CW's you (we) would still have the chance to level up our clans!