Two or more rule instances available to you can have the same names but different rulesets, or the same ruleset but different version numbers. These are known as siblings.
During rule resolution, only one of these is found. It masks or overrides the others.
By definition, a final rule cannot be overridden. If the final rule is class-based, rules with Applies To class values derived from the Applies To class of a final rule can supersede the final rule, within an application.