The wording says
Twist: If there is a Villain on the Streets or Bridge, put this Twist in a stack of "Western States Victories." Otherwise, if there is a Villain in the Sewers, put this Twist in a stack of "Eastern States Victories.
I get that they went pseudo-thematic with the City spaces on the left being "West" and the one on the right being "East", but apparently the "Middle" of the U.S. doesn't matter? These seems like a seriously neutered Scheme, or am I missing something? Even a 3-2 split would make sense if you consider the Mississippi River as a divider....
edit: I should've put this in the actual Civil War forums, but I can't delete it to redo it over there. Sorry.