What I'm stating is, in a match against an Antagonist, when you're playing with a low level team, who are being farmed by the Antagonist, how about dividing all the lives of the team up and giving each player a death cap that after 'x' amount of kills any more kills on them won't register?
This way, it stops Antagonists picking on the weaker members of the team and that in order to bring about an end of the mission, everyone has to be killed the same number of times.
Now I can't quite remember how many deaths you need before Cortez goes off to get Aleph, but hazarding a guess, say 12 for the first run, 14 for the second run and of course the 6 in sudden death, that means, a total of 32 kills by the Antagonist to win. They would have to kill each player 8 times in order to gain victory. Of course this number will go down, is the environment kills them also.
This is a complicated mechanic, but a fair one. Then again, MSE, just give us a PvP option please???