Herculean vs built like a tank

Herculean

adj
  • Of extraordinary might, power, size, etc.; suggesting Hercules in size or strength. 

  • Requiring a huge amount of work; of extraordinary difficulty. 

built like a tank

adj
  • Broad-shouldered and of solid, muscular build. 

  • Sturdy; exceptionally well constructed. 

How often have the words Herculean and built like a tank occurred in a corpus of books? (source: Google Ngram Viewer )