It says on p. 12 of the rulebook:
If two Chaos cards played to the same region would
otherwise happen simultaneously, the left-hand (i.e.,
eastern) card is resolved frst, and the right-hand card
Then on p. 18 there is an example where the Nurgle card (+1 defence for Nurgle units in the area) takes effect before the Khorne card (roll two dice before combat), i.e. Nurgle benefits from the +1 defence during Khorne's pre-battle rolls. The cards are pictured that the Khorne card is to the left. Wouldn't it be possible for some rules lawyers to argue that the Khorne card "happened first" and therefore Nurgle doesn't get their card's effect during the pre-battle rolls? Or is the Nurgle card considered a "permanent" (well, until the end of the round anyway) effect? If so, shouldn't it be spelled out more precisely?