The formation rank unit state is more specific in its function than that.
Move command + click: Go to the target point at best individual speed.
Move command + drag: Assemble in formation along the dragged line at best individual speed, with formation rank determining whether each unit is in front of, on or behind it.
Move command + control-click: Assemble around the target point in a formation identical to the current one, matching speeds with the other selected units.
For the result you want, you should line move the units into formation first, then control move them.
