just so vs smack-dab

just so

adv
  • In the precise manner indicated. 

  • Used other than figuratively or idiomatically: see just, so 

smack-dab

adv
  • Exactly in a place, especially the middle; directly; precisely; dead-center. 

How often have the words just so and smack-dab occurred in a corpus of books? (source: Google Ngram Viewer )