I give you credit for calling that one! I never had the pleasure of reading the book. Huge mistake on my part. And, it has been many years since I watched the movie, which came out just about the time I graduated (1974), that I do recall. A quick check on IMDB reveals the film debuted in 1975.
I will set aside the cold, winter nights this year for reading that book, and get back to you on my impressions of the characters. Yours is an interesting perspective.