Personally, if the random game thing decided to put me up against my own team, the side that needed wins more would end up winning.
I've gone the route of playing one toon, with someone else playing the other toon, and running two's... so will never be in this situation.

It might be because both sides spammed DPS, but the side I was actively controlling one toon on, managed to manually (not part of spam) get off a Hungering Cold, while both sides forgot Trinkets and were spamming their single target Obliterate sequence.