>>45092487Broken abilities on Clefable, lack of reliable recovery (Soft-Boiled) and usable defense stats, that’s literally it-
Assuming you at least gave Wigglytuff 60 on both defense stats (so its high HP is actually usable) and Soft-Boiled, it could probably be a respectable RU mainstay. However, to be close to Clef’s viability it would need a great ability like Magic Guard or Unaware to even come close.