If the game could use sub-classes, it would be a nice touch to it considering alot of people will be the same basically.
Example:
EternalDream chooses soldier as main class.
Ero chooses soldier as main class.
EternalDream chooses Berserker/Axeman(Axe-user) because of the benefits for heavy hitting skills, slashing damage, Higher HP bonus, and wonderful offensive abilities. While suffering from slow-hit rate, lower defense-type things implemented in the game, and restricted to only wear Light or Medium-based armor due to the fact of the Berserker's disdain for heavy armor to restrict his movements.
Ero chooses Dragoon/Spearman (Spear-user) because of the long-reach during battle (if that matters), piercing damage, bonus to attack/or something on horseback, Chance of ignoring percentage of opponent's armor due to piercing effects while suffering from limited skill selection, average defense, ect, ect...
I could go on and on. Lol, but that's just random things that could make sub-classes interesting and everyone won't be the same exact "soldier". It could even effect tasks outside of battle, that would be nice. Or even if sub-classes was for cosmetics..