The orbs do not disappear post death. The orbs being pumped out by the gunslingers are also scattered sufficiently to allow the defenders to recoup and be up on running on less than a minute. In theory, perhaps it is possible to pop the bubbles but with the blessing and armor stacking these guys are tough to kill and a full team wipe is unlikely. Again, the orbs of light on the ground do not disappear after death, at most a striker fist would just scatter them around a bit.