If you go to the Metallica page and look at Similar Artists, you'll see that Megadeth has 395 votes.
If you go to the Megadeth page and look at Similar Artists, you'll see that Metallica has 393 votes.

I went to check out why by clicking on the "edit" and then the "84%" on both pages, and I noticed something. One user's vote, tonhaoslayer666, has been glitched. His vote appears under the "AGAINST" section in Megadeths Page but is in the "FOR" section in Metallica's.

https://www.metal-archives.com/bands/Metallica/125
https://www.metal-archives.com/bands/Megadeth/138
https://www.metal-archives.com/recommen ... bandId/125
https://www.metal-archives.com/recommen ... bandId/138