mix it up vs ply weapons

mix it up

verb
  • To create one or more variations of the usual way in which something is done. 

  • To compete vigorously, to quarrel, or to fight physically. 

  • To engage with people, relate to people. 

ply weapons

How often have the words mix it up and ply weapons occurred in a corpus of books? (source: Google Ngram Viewer )