insubstantial vs schematic

insubstantial

adj
  • Lacking substance; not real or strong. 

schematic

adj
  • represented too simply or in an overly formulaic way, reflecting a shallow or incomplete understanding of complex subject matter 

  • sketchy, incomplete 

  • relating to a schema 

noun
  • A simplified line drawing used by scientists, engineers, technologists and others to illustrate a system at an abstract level. Schematic drawings often use standard symbols for clarity. 

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