grist for the mill vs vantage

grist for the mill

noun
  • Something that is useful or that creates a favorable opportunity. 

vantage

noun
  • A superior or more favorable situation or opportunity; gain; profit; advantage. 

  • A place or position affording a good view; a vantage point. 

How often have the words grist for the mill and vantage occurred in a corpus of books? (source: Google Ngram Viewer )