I would suggest that the leader can then move his free foot without moving his upper body and expect the follower to mirror this, without looking at his foot. When the leader has placed his foot in the desired position he will then move his weight onto the foot and follower will do the same.
The lead for this movement (i.e. the follower sticking her free leg out) is a tiny impulse in the direction the leader wants her to place her foot, without him taking a step and doing a weight transfer. As soon as he's sent this impulse, he can then move his own free leg/foot however he chooses (in the same direction or any other). If executed properly, this creates the illusion of simultaneity. This is the same fundamental technique used in walking, just broken down into its constituent parts.
It seems to me that your method requires the follower to look at the leaders chest or be behind the leader or be pushed by the leader and whatever the case, cause the follower to snatch her step.