Tiers don't go by an arbitrary top 53, a common misconception.
Instead, they go by the equally arbitrary 3.4% usage, which puts Duggy pretty firmly in NU.
Isn't 3.093 UU though, I'm pretty sure it is at least... :/
Btw i didn't say Duggy should be OU, I know perfectly well that it doesn't go by the top 53 pokemon. X_X