impugn vs submit

impugn

verb
  • To verbally assault, especially to argue against an opinion, motive, or action; to question the truth or validity of. 

submit

verb
  • To win a fight against (an opponent) by submission. 

  • To yield (something) to another, as when defeated. 

  • To enter or put forward for approval, consideration, marking etc. 

  • To yield or give way to another. 

  • To subject; to put through a process. 

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