butt heads vs have it out

butt heads

verb
  • To argue uncompromisingly. 

  • To struggle against something that does not give way. 

have it out

verb
  • To argue in order to air or resolve a conflict. 

  • To confront (someone) with a view to settling a conflict. 

How often have the words butt heads and have it out occurred in a corpus of books? (source: Google Ngram Viewer )