As others have commented, there are a lot of mythical profiles on WikiTree. With the advent of pre-1500 certification we don't create new ones, but WikiTree policy is not to delete old profiles.
Therefore the idea of categorizing these old profiles as to what myth they appeared in is an excellent one; subcategories under Norse Mythology. That way the profile does what WikiTree needs it to do -- it tells the truth, although this time the truth is not about a life lived, but about a legend developed.
Myths often start out with a god or two, work down through completely fictional names, then through real people with embellished stories, and finally several generations of real stories about real people. All can get the myth category, because the biography will identify what is real and what is not.
Since WikiTree adopted the standard formatting of Biography (mandatory), Research Notes (optional), Sources (mandatory) and Acknowledgements (optional), I have been formatting mythical profiles with just a sentence under biography stating that this person never existed, and then under Research Notes starting to identify a chronology of what sources carry the legend and what they say about the character; often the legend is short and simple in the earliest version and expands in the latest. The profile then becomes the story of the character in legend, rather than the story of a real person who was born, married, fought battles, had children, and died.
Once you are describing a legend or a character in a legend, and what the legend says that person does, it would seem that Snorri becomes a quite useful -- and legitimate -- source.