In Artifactory, once the repository type is set, the system will index artifacts and calculate the corresponding metadata for every package uploaded, which optimizes performance when resolving artifacts.
That being said, Artifactory Generic repositories do not maintain separate package indexes because they are not specific to any package type. For more information, see Generic Repositories.
The Repository Layout configuration in each repository sets the layout that the repository should use for storing and identifying modules. Hence, the layout that corresponds to the package type defined will be used to index packages uploaded that match the selected layout and calculate the metadata accordingly.