I advice not to start deleting and copying GUIDs, leave the Wavlake releases as they are. What artist name Wavlake creates for you doesn't have anything to do with your self-hosted releases, the names doesn't overlap. Think of it like this, what is made on Wavlake only exists on Wavlake, they only make feeds to the Podcast Index with a name written down in the 'name' tag. Just try self-hosting something, and then I'm sure you will see how it works. There are simply no right answer on how to. There are even artists that releases both on Wavlake and self-hosted, with the same release.