generalship vs headship

generalship

noun
  • The position or office of a general. 

  • By extension, leadership, good management. 

  • The skills or performance of a good general; military leadership, strategy. 

  • The term of office of a military general. 

headship

noun
  • The position of a head or chief. 

  • The position of a headmaster or headmistress. 

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