Questions about the gameplay of Heroes 6.

The question is complex, but important. When I played through the campaigns, I chose different paths for the heroes; for some, the paths were fitting, and for others, not. I did it out of curiosity. Now, I've completed all the campaigns, and in the Dynasty mode, the heroes have their initial classes and paths (mage/warrior, evil/good). Is there a way to change this for duels, like replaying the campaign or editing the files to cheat something? I'm interested in the opinion of those who definitely know.