Rogues have a couple advantages to 2-handed fighters.

They have much better cc moves. 2 stuns, a knockdown, a charm, and a blind. The charm, in particular, is amazing.
They have a built-in haste, and a built-in invisibility.
Their weapon uses fewer AP, meaning you can almost ALWAYS afford to attack. You never end a turn with a bunch of AP you can't spend.
They have a naturally very high movement speed.

Their survivability isn't as good, and they deal less damage overall.

A Bully+Guerrilla man-at-arms vs a Bully+Guerrilla+Backstabber scoundrel, the man-at-arms will almost certain do more damage, and requires 1 fewer talent.