Second this!
DAO is not World of Warcraft or a typical dungeon brawler.
It's a game built around a complex story, with multiple paths through that story. That flexibility means that there's no single "ideal" party, and that there will be multiple ways to achieve most game objectives (including winning combats).
Also, it sounds like you're trying to charge through every combat and turn the game into one long frontal assault. Bioware's pause-and-click combat system is designed for *tactics*, not tanking. Each combat demands a different approach, and your party members' relative strengths and weaknesses change as they level.
I think you're missing a lot of the game's depth and making a lot of unnecessary frustration for yourself.
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