fall in with vs run up against

fall in with

verb
  • To meet with (something). 

  • To accept, abide by (a set of generally agreed rules, or a suggestion). 

  • To join (a group of people). 

run up against

verb
  • To begin to encounter problems with (someone or something). 

How often have the words fall in with and run up against occurred in a corpus of books? (source: Google Ngram Viewer )