Every player in WvWvW has an aura that stacks with others :
+x toughness
-1% mouvement speed.
So when you run a zerg you siege them keep, but you are extremely inefficient at roaming around the map.
Big problem right now is that if you wanna run around capping camps and killing dolyaks, it’s more efficient with à zerg than with a small group.
Otherwise would really appreciate titles and à commander rework.