ground pounder vs guardsman

ground pounder

noun
  • A military soldier whose primary role is infantry or the use of ground-based materiel. 

guardsman

noun
  • A person, especially a soldier, who is on guard. 

  • A member of a Guards regiment. 

  • A member of the National Guard. 

How often have the words ground pounder and guardsman occurred in a corpus of books? (source: Google Ngram Viewer )