You can put one plant that you give all the light to in there and leave it in veg until it gets half the size the tent can handle, then flip to flower.
Or you can put 20 plants in there to share all the light, and give them no time to grow in veg and flip them right to flower.
I’d personally put two plants in the 4x2 and Scrog them into an even canopy.
One plant can produce the same amount as multiple. It depends on light, container size, tent environment, strain etc.