What if instead of being completely incompatible, Sharpness, Smite, and Bane of Arthropods could be placed on a single sword as long as their levels added up to 5 or less. So you could have Sharpness V, or Sharpness II Smite III, or Smite IV and Bane of Arthropods I, etc.
#Better sharpness compatibility
trim oriole
inner echo
this is a cool idea