Very silly indeed, If i have 3 1000watt lights, Two 400 watt lights do not equal the same lumen count, even using your chart's you can figure it out for yourself.
At 7' Inch's away from tops:
3 1000watt lights = 392,886 Lumen's
At 7' Inch's away from tops:
2 400watt lights = 93,544 Lumen's...