Luna Mortis would have been bigger about 5 years ago, if they toured with bands like In Flames, Haunted, etc.
Saw them at Powerfest.
Not a bad band, but that sound is SO dated nowadays.
As others have said, their addition to the tour will not help ticket sales.
Sorry, as much as I like Primal Fear, they are still VERY unknown to the mass metal market in the states.
They need to hook up with like a HammerFall or Kamelot.
Sure, it might mean less $$$ in their pockets, but it will have a stronger long term impact, if they desire to return to the States.