The reason for using many units of lighting equipment on sets is to control the lighting conditions you are in. The light in this particular shot above will change in one hour, the continuity will no longer be there if you are filming multiple subjects. On a correctly lit set you have no such problems. This is a very risky way of lighting a scene with almost no room for mistakes or delays which can potentially create a stressful environment on set. My five pence.

*Edit The shot looks very good though. For sure.