incommensurable vs mixed bag

incommensurable

noun
  • An incommensurable value or quantity; an irrational number. 

adj
  • Not able to be measured by the same standards as another term in the context. 

  • having a ratio that is not expressible as a fraction of two integers. 

  • having no common integer divisor except 1. 

mixed bag

noun
  • A group of entities with few characteristics in common. 

  • Any bag containing a mixture of something. 

  • Something tending to have both good and bad results or characteristics; something having a mixture of advantages and disadvantages. 

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