lock horns with vs mix it up

lock horns with

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. 

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