Rob Zombie is billed over Marilyn Manson at Rock on the Range.
Manson headlined Mayhem 09 over Slayer.
Slayer headlined a tour over Zombie last summer.
So they're all pretty close in popularity. This could really go either way for this tour. The RotR billing is most recent, but Manson just had an album come out. I think Manson may have the slight edge due to that alone, but it will still be a co-headliner obviously either way.
Plus, all of his haters can leave after Zombie.
12/15 - Trans-Siberian Orchestra
2/4 - Gojira/Devin Townsend
2/23 - Muse
3/2 - Dropkick Murphys
3/11 - Meshuggah
3/12 - Tenacious D