I'm going to break the topic a bit, but logically, Smeargle in general.
Yeah yeah, it's all explained with "Sketch", but how would a Smeargle actually manage to use something like Needle punch or Gunk Shot, or Gastro Acid?
Will its arm magically sprout thorns or always keep a trashcan nearby? Or imagine a Smeargle chucking its entire stomach.
"Sketch" doesn't logically explain how a Smeargle would physically be able to do these moves. Makes me wish it was actually in the anime, to play around with this comical idea.