Zardnaar
Legend
The reasoning I thought of as a youth when reading the weapon tables in the 2nd edition PHB was simple; to create a "right kind of weapon for the job" situation. Big weapons are best for big enemies, but smaller weapons work fine for smaller enemies.
Though later 2nd edition sort of turned that around on me by having the optional critical tables make bigger weapons better for critical hits no matter what sort of enemy you were facing, but especially if the monster was a smaller size category than your weapon.
I kind of liked the weapon rules in combat and tactics as they errated a few of them and large weapons often sucked in AD&D due to being very slow.