By definition, final rules cannot be overridden. However, two final rules with the same visible key can arise through importing a ZIP file containing rules, or through other uncommon techniques. Such final rules are conflicts.
As a best practice, eliminate final rule conflicts during development, because the rule not marked final is (incorrectly) never executed.
Use the Final Conflicts report Rule-.ListThisRuleFinalCollisions.ALL to find final rules that both have the same name and same other visible key parts. Eliminate any conflicts by deleting one of each conflicting pair until this report is empty. To access this report, select > Application > Inventory > Inventory Reports. Select Rule as the Category and enter "final" as the Search Text.