I've been flawless more times than I can count with all 3 classes. I'd much rather face 3 warlocks than 3 hunters. Self res is so easy to counter. 90% of the time they use it when it is a 3 on 1 and they will easily be taken down. When they burn it early you can still kill them quickly with a shotgun or sniper. If self res is your biggest problem, you are not really ready to compete in trials anyway.