Well, I never really paid attention to how it played out in battle, but that's what the character sheet said anyways. It was usually 20-40 points higher than everyone else's. I probably wouldn't have noticed if I hadn't also read several people say that rogue dual wield was OP. There were probably referring to playing Hawke as a dual wield though, I dunno. I doubt positioning would be as much of an issue there.
DPS only refers to their damage during regular mash A(Or whatever on keyboard) attacks. Doesn't reflect well to what damage they would do with abilities all to well. Without a Vendetta or Assassination all she really brought to the table was the AoE back stab. And your two other rogues completely eclipse her in terms of AoE damage.
I haven't finished my Bow run through but I know Dual wield hawkes can be a beast if speced right. Although whenever that nerf came down(Sometime after Sebastian DLC and before Mark of the assassin. It happen when I wasn't playing the game.) It took a serious blow. I use to be able to maintain 100% crit hit rate with a really high crit hit damage and be able to tank 1 high ranking enemy. When I picked up the game again and instantly noticed the nerfs when my Dual Weild rogue was getting beaten up much easier. I notice a lot of her stats went down on the char status screen. I still could deal 5 digit damage with the brittle multiplier.
They also nerfed armor for Blood magic. However I do feel the game was balanced at least in mage and warrior land. I have to finish my bow play through to make an accurate assessment of rogue.
If cookies were milk and milk was cookies. Would Oreo's still be america's favorite brand of milk?