I would love to see this as part of a +/-5, +/-10 Degree of Success system with d20 tests. If you want to go old school, Cindi Rice's swashbuckling rules from Dragon magazine #232 in 1996 looks brutally complex nowadays but was the first time I saw this done and sold me on degree of success in combat.They should crib from PF and have properties that trigger if you hit by 10+. Disarm with flails, knockdown with hammers, ongoing bleeds, etc. Siloing any degree of complexity to spells and spells alone is poor design.
As it stands, a 1 or 2 point difference in damage by weapon type is dull. I'd rather see mechanics matter in an interesting tactical way rather than a minor math bump.