Base formation should look similar to a 4-man cup. The mark is very focused on taking away the around break. This zone is designed to take away as many upfield options as possible with less running than other zones at the expense of allowing dumps and some swings.
Disc is swung to a sideline. Unless there is a strong crosswind, this zone is designed to force middle. With experience, the force should be able to switch silently, as we are always forcing back to the middle.
As the disc approaches a sideline, the opposite wing (#3) drifts to a central location, allowing the monster to remain as deep as necessary. Because of the sideline, the mark does not have to be as focused on the around, and can help defend the sideline.
The three remaining wall players are on a diagonal line to take away the open area left by the mark.