In a horizontal stack, the downfield cutters (the offense) line up in a row. One advantage to this formation is that cutters are already spread out to attack both sides of the field.
Typically the middle two cutters are considered primary targets and are responsible for initiating cuts. One going deep (6), while the other going for the under (5).
The secondary cutters on the outside are timing their movements to continually cut if the throw is made, otherwise they fill in the empty space that the initial cuts create. This example demonstrates cutters who rotate across the field.
Let's reset to review an alternative strategy involving the cutters staying in their respective vertical lanes
The middle primary cutters initiate as before, with the secondary outside cutters doing the opposite of their partners.
Instead of cycling back across the field, cutters move like pistons in and out. 5 and 7 would go deep, while 6 and 4 cut back to the thrower (continue this cycle if no one is open).
Additionally, when the disc moves to one of the side lines it is recommended for the secondary cutter on that side to clear out in order to create more space for people cutting towards the thrower. Check out the next play, where we are forced to adjust based on a defense.