I think the rogue is quite efficient in combat and generally all classes more balanced. Now I play only with 2 characters (rogue + mage) and they give me lots of different strategic options. Some fights, especially later in the game, are quite easy.
Sorry, but I can't agree with you. Can you name some examples?

In my current play through I play as a rogue & mage as well, but especially later in the game are pretty difficult.