If you are killing the rogue early in the fight (or trying to), I think you're making a mistake. Enh shaman and warrior would be my two first targets, then you need to kill their healers/rezzers.

In most of my wins, the rogue is one of the last players to die, unless I get one opportunistically after splash damage from a fire nova totem blast or a NS+EM+CL combo.

I would kill the priest after your first 1-2 kills since they are going to mana burn you and are a potential rezzer. Don't be afraid to turtle up, reset your totems, and camp bodies for a bit mid-fight to regen mana and draw them out again.

Hope that helps?