sort out vs straighten out

sort out

verb
  • To fix, as a problem. 

  • To provide (somebody) with a necessity, or a solution to a problem. 

  • To separate from the remainder of a group; often construed with from. 

  • To clarify by reviewing mentally. 

  • To arrange. 

  • To organise or separate into groups, as a collection of items, so as to make tidy. 

  • To attack physically. 

straighten out

verb
  • To correct or rectify. 

  • To make straight. 

  • To tidy, neaten, or organize. 

  • To eliminate confusion from or concerning. 

  • To correct; to stop doing something wrong. 

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