mountebank vs smooth operator

mountebank

noun
  • One who sells by deception; a con artist. 

  • One who sells dubious medicines. 

  • Any boastful, false pretender. 

verb
  • To act as a mountebank. 

  • To cheat by boasting and false pretenses. 

smooth operator

noun
  • A skillful, manipulative person, con artist, or clever scoundrel. 

  • A person who accomplishes tasks with efficiency and grace, especially one with verbal skills who is persuasive in interpersonal relationships, negotiation, etc. 

How often have the words mountebank and smooth operator occurred in a corpus of books? (source: Google Ngram Viewer )