120W LED, how many plants?

120W LED with 4240lumens, covers more than 25sq feet, so if the light covers that much space then how many plants could you put under the light so they all get even (it can't be that you can get good light for all that space)? The size of LED box is 400(L) x 212(W) x 62(H)mm

They said it should cover a 2x2 area for 120-180w led. You could possibly even do a 3x3 but that would be stretching it. I would say you could put 4 plants under.

So under 120W LED I can grow as much as I can fit in ~ 2x2feet box and then plants will get maximum light?

Then, with 250W LED in 3x3 or 4x4feet box will be enough? And how the light of LED lamp goes, do I have to put the LED's (not the whole lamp but only the LED section) directly under plants or the light will spread around the box evenly?

Any ideas?