Head it back, and beat the marker to finish. The back-post man knocks it back, and the second man times his run past the defender to finish first-time.
As the base, but a defender marks the second man. Emphasise angling the knock-back into the danger, and the second man timing his run to beat the marker to it. Rotate the roles.
Fork it into your private drills, then change the animation, adjust positions, swap equipment, or drop it into a session block.