In my initial builds of SkyRPG (Now officially named Heroes By Trade) I built classes around functional lines. Each class could be melee or range oriented, use magical or physical attacks, and either focus on pure damage or a mix of damage, disruption, and buffs. After finishing my eight classes though I looked at them and they didn't have a huge amount of pizzazz and pop. They had all kinds of interesting abilities and mechanics but the flavour sections didn't do much to leap off of the page.
Example 1: Marauders focus on high damage attacks using melee weapons. They rush in and smash their opponents in close range; although Marauders have limited defensive options they hit harder than any other class.
Example 2: Marauders are melee fighters that employ techniques from various animals to decimate their enemies. They use weapons but their powers allow them to pounce like a cheetah, gore like a bull, or poison their opponents like a snake. All of their abilities are based around emulating the powers and abilities of various creatures and because Marauders can employ the strengths of any animal at any given time they can accomplish unthinkable feats in combat. When a Marauder charges their targets recoil in fear for they know that the mightiest predator in the jungle is coming and will not be stopped.
The second entry is obviously more interesting and can act as a springboard for stories and interesting roleplaying. The trick is that if people want to play a melee brawler but aren't interested in the animal kit they really have no other option. In DnD the base classes have very little in the way of lore but the extra classes and especially the classes added in extra books are loaded down with fluff and bizarre themes. What I am wondering is whether or not that is a sensible formula. I could easily build a few generic classes and a few colourful ones but I could also go full on either way; all lore filled or all generic.
What I wonder is what people like the best. Constraining people's choices to some extent is good because it forces them to be a bit creative to make the system reflect their imagination but going too far means the system feels too constrained and might be unusable in a given campaign setting. I don't know where the best balance lies; if you have an opinion on it do drop a comment and let me know.