Rather than making weapons train 1-to-1 on all successful hits, make them train differently:

• Weapons train only when their natural damage die rolls a 1 / rolls a max (ignoring other weapon damage bonuses), so that weaker weapons train faster than stronger ones, and weapon skill for stronger weapons comes in later in the game rather than having all players reach Expert relatively early in the game. This has the oddity of incentivizing orcish weapons over regular, elven or dwarvish though.
• Make the enchantment of your weapon irrelevant to training or even make training slower with a positively enchanted weapon; if the weapon has magical homing assist technology, you’re not really building skill in how to use it that much.