Amazon calculates a product’s star ratings using a machine learned model instead of a raw data average. The machine learned model takes into account factors including: the age of a review, helpfulness votes by customers and whether the reviews are from verified purchases.
While as a collection of movies based on the one iconic character by the late great Tom Clancy, there is a lack of consistency among the movies and all are better thought of as stand alone. As Baldwin, Ford and Affleck all play a drastically different version of Ryan. Baldwin and Ford are in the one series whereas Affleck's Ryan is a reboot. Still there is plenty to be had in these great films. While they do depart from the books they still are highly entertaining.