I argue that class abilities are sufficient to define a starting point for a character, and to give said character basic abilities for that archetype. Everything else is so open and customizable as to allow for endless customization and variance.
I present two fighters: Arkosh and Zednat. (Just roll with me.)
Arkosh is a lawful-good, human, 1st-level fighter whose vital stats are: HP 10, AC 13. His primary attributes are Str, Con, Cha. His significant attributes are: Str 15 (+1), Cha 16 (+2). He carries studded leather armor, a longsword (with which he attacks at +1), a dagger and a really nice pair of boots that his uncle Gerald gave him. He has a secondary skill of Woodsman. He is kind of a Boy Scout, strives to do the right thing, and never lies.I just wrote those up, too, off the top of my head. That's 2 1st level fighters, who have the following in common:
Zednat is a chaotic neutral, human, 1st level fighter whose vital stats are: HP 10, AC 13. His primary attributes are: Str, Int, and Wis. His significant attributes are Str 15 (+1) and Wis 8 (-1). He carries studded leather armor, a staff (with which he attacks at +1), a shortbow and a collection of belt buckles. He has a secondary skill of Sailing. He is bad at making decisions but strives to be wiser (in fact he's unaware that he's kind of gullible), and he has an eye for the ladies.
- Same hit die;
- Same Prime from class;
- Same +1 bonus with 1 weapon;
- Full HP for their class; and
- Same armor.
The ability to pick primes lets you define a fighter however you want: sure, one prime goes to Strength, but the other(s)? Why not stick the other prime on Intelligence and make a smart, tactical fighter? Charisma, for a swashbuckler-type -- or an intimidating bully? Wisdom, for a girl who's kind of introspective? Humans, of course, get two more primes to play with -- just like Arkosh and Zednat did.
Thieves have a lot more class abilities, but I advance that the difference between a street urchin who grew up in Lankhmar, where he learned his thieving abilities, and a clever servant girl who taught herself to listen at palace doors for juicy gossip (and sneak around corridors at night in search of it) is merely one of concept, and nothing in the rules requires or prohibits that.
If I'm missing something, I welcome comment!