The three advantages they have over Wizards are the Move and Cast

Priest Info: Priests are quite unique in ways. Only support really, but some Priests can deal out better damage than some Wizards if they use Magnus on enough enemies. It really depends on how they're built. However, they rarely die due to their Level 10 Heal and high martial empires gold INT stat.

Sage Info: Definitely harder to play than Wizards due to their lack of powerful spells. I think Gravity intended us to use them to fight physically as well, which most Sages never do.

The three advantages they have over Wizards are the Move and Cast, Double Cast, and Magic Rod.

Bard Info: Not nearly as cheap as Hunters. They are more built for support, and can be catastrophic when combed with a Dancer. Also, they don't use traps, and don't have an annoying bird.

Dancer Info: Same as Bard.

Alchemist Info: Alchemists are difficult to play, due to their lack of good combat skills, and the fact that most of the time, they will be relying on their monsters, which will not grow stronger, and because of that, will lose a lot of power in the high levels, and dangerous areas.