Again the math shows Nashor's by itself doesn't compare to Wit's or Malady by themselves for damage purposes (at least not on E). I honestly see people running up to Teemo all the time going "Oh he's squishy let me kill him real fast...WTF?!?!?! How did I die so fast" And really, how many champs outrun Teemo?
If your build works for you by all means use it, I was just sharing some observations.