John Thompson's V vs. Schaum 6

[sassafras]

When I studied John Thompson IV and V over 30 years ago, they seemed much more difficult that Alfred Adult III and Schaum 5 (Amber) and 6 (Grey) which I am using now as refresher books.

I don't have a Hinson or Magrath so could someone tell me how the methods books compare in reality as to the usually alleged 10 piano levels?

What levels are the John Thompson III, Iv and V in reality?

I know that years ago after finishing Thompson V it only took a couple of months to play Rhapsody in Blue and I was playing Rachmaniniff, Liszt and Chopin consistently, along with popular and movie music.