I also think that Dalton was evil all along(much cooler), and the Queen's evilness just arose from the Mammon machine. It makes more of a difference to me that Dalton always was so dedicated to evil and the Queen was just under the influence of Lavos and was more misguided.
I'll give you that. It's an important character difference. I wonder what he was like before the Queen went crazy. The problem with video game villains like him is that there's no plausible explanation whatsoever for how they came to be trusted with such power and authority in the first place. The Kingdom of Zeal, with its three gurus and love of learning, set itself up as a place for merit to be recognized, yet Dalton's only merit is that he is damn sexy...which has nothing to do with the security services for which he is supposedly responsible.
It's possible that we're both mistaken and that he too was corrupted by the Mammon Machine somehow, although unlikely. More likely is that Dalton was a symbol of everything wrong with the Kingdom of Zeal: a case-in-point which proved that the kingdom was not so paradisaical after all: If someone like
him could rise to be so entrusted with the people's safety, then clearly Zeal did not care about its people's safety. A similar, but distinct possibility is that he was corrupted by the breakdown of the royal family, an example of the Japanese cultural attitude of one's own failures having ramifications for one's whole family. We don't know for sure how King Zeal died, and Queen Zeal's corruption may have been the last straw for him.
But it's also possible that he was just a bad egg, rotten apple, scum of the bottom of the barrel kind of a mook right from the start.