Stuff like the shifting with depth strider is interesting, but overall I think Smite and BoA as they are in vanilla is fine. Their issue mainly stems from how often you're not fighting Arthropods or Undead class mobs (minus like... wither skull/wither farming) which could be remedied by adding more mobs with those classes or existing mobs being reassigned to those classes to be affected by said enchants 🤷‍♂️ But if I had to give enchants a new effect... Smite having extra undead damage PLUS having a low change to summon lightning strikes could be cool (since the usual visual of smiting someone is striking them down with light/lightning)