I'm genuinely surprised that there are people who have issues with endgame dungeons. Everything past Karrundax can be beaten with 2 people on the boss, 2 people on the adds and the obligatory GF running around with their shield out doing god knows what. It's possible to be disgustingly disorganized and still do just fine…
For rogues especially, it's cleric or nothing: and most of the time, it's nothing, considering that the poor cleric companion seems to have a magnetic attraction to enemies, causing them to throw out attacks that you wouldn't have to deal with while stealthed.
The problem with this is that people will start instantly surrendering once they get behind, even in a winnable match, and ruin it for the few who want to play things out. The nature of Domination is that if a team is winning by an overwhelming margin, the match speeds up anyway. Not to mention that we'll get premade AFK…
Rogues are easily kited: you have range and 20 kinds of CC, and comparable damage on your normal attacks. Just dodge the Dazing Strikes and choke them whenever you can.