The file names are <the order of the file>_artist.*, it just so happens that you can therefore find the artists responsible for the works by going to https://weasyl.com/~<artist name>.
There should be no mistagged files, as none of them depended upon being tagged in the first place.
This may not actually have the artwork with the most favorites because I only let it index the first 2100 pages of art on weasyl.