Higher province number moves first?

[thejeff]

I'm not sure I follow your example, but I think you're missing something.
There are three phases of movement. Ritual, friendly and hostile.
All movement within a phase is assumed to be simultaneous. It doesn't matter whether Agartha or Pythium moves first, when the movement phase is over, Pythium's army has moved on and Agartha's has moved in.

One edge case where movement order might be important are when both armies are moving into each other's province. Then it usually looks like one has moved first and kept the other from moving. A->B, so B cannot invade A. If B had been invading C, he would be gone. My argument is the rare cases where both armies move, switching provinces, or neither moves indicate that this is not being done based simply on arbitrary movement order.

The other case where movement order might matter is when 2 nations invade a third party's province. It is more likely that what order the nations fight is based on some kind of id order, though one invader will always fight the owner first.