many vs some kind of

many

det
  • Used to indicate, demonstrate or compare the number of people or things. 

  • An indefinite large number of. 

noun
  • A considerable number. 

  • A multitude; a great aggregate; a mass of people; the generality; the common herd. 

pron
  • An indefinite large number of people or things. 

adj
  • Existing in large number; numerous. 

some kind of

det
  • Used other than figuratively or idiomatically: see some, kind, of. 

  • A remarkable. 

  • a mediocre; a bare minimum; (denoting that something only barely fits a certain category, or is very mediocre in it) 

adv
  • Used as an intensifier of adjectives: remarkably 

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