Differences within categories:
This idea is based on a factor that differentiates one weapon from another within the same category (Swords,Bows,Orbs)
Different characteristics that differentiate them such as the attack speed and the basic damage enhancer of the weapon, as well as special uses in certain equipment.
Taking stats as a powered base depending on the weapon.
Wide Sword has: 35% Attack speed / 88% Damage power
Cheese Sword has: 67% Attack speed / 35% Damage power
Depending on what bow is, it'll have a counter effect. (Including different attack speed)
> Extra damage against flying enemies
> Piercing arrows
And those are just a few examples.