Order of Magical Battles: Specials or Nationals?

[Chazar]

I thought that battles are only resolved after the sides have been set up, i.e. ordinary battles take place after all movement has been calculated and 'battles triggered by magic' take place only after all rituals have been cast and evaluated (I think except assassinations like ashen angel, which I think are evaluated on the spot). So all critters from one side should fight together in one magical battle...

But how about neutral critters like GhostRider being sent from different sides? Do they fight together against whatever else is there?