overman vs weigh on

overman

verb
  • To provide with too many personnel; overstaff. 

noun
  • A person with great powers; a superman. 

  • A person who supervises others; a supervisor, especially in a mine. 

weigh on

verb
  • To cause distress to or impose a burden on; to trouble. 

How often have the words overman and weigh on occurred in a corpus of books? (source: Google Ngram Viewer )