John Thiel wrote, "His characters don't fit the description of good men at all. His heroes cut men down in their tracks and sell out the bandits they congregate with. The only morality in them is "stay alive".
Can't speak for Dumbledore since I haven't read those books, but Gandalf might appear to be lacking intelligence, Psi, because he takes the moral dimension into account. Conan would just use the Ring for his advantage, right? If he became a Dark Lord, he'd have no problem with that, would he?