There is nothing in the rules that say two players cannot occupy the same spot on the board, unless I missed it. There is a statement that the player on a Location can continue to scout the Location without moving off. If two players can not be on the same spot, then ideally a player will block a Location since they do not have to step out and back in.
Can a player use a Location to walk through? One section of the rules make it seems like you may stop to scout, which implies it can be used as a space. While another section makes it sound like you must stop and scout, therefore you cannot enter the space unless you can scout it.
For what its worth we have always played the competitive game not allowing two player characters to occupy the same space, whether stopping together or moving through. In the competitive game, the rules specifically do allow it, but I have never played that version.
The rules do state that when you enter a location or resource space you must stop and deal with the given space. When we play, we don't allow players to enter locations unless the location is one of the available scouting locations. The reason we do this is because a zombie token is not left in a location when moving out.
I would say just play it the way it makes most sense to you and those you play with. This obviously is not a serious game, just lots of dice rolling fun!