Yeah, it would really depend on your strain.

If your strain grows tall and skinny, you just harvest the main cola, you can fit more per light.

If your strain grows out and bushy, less will fit.

Also depends on how long you keep them in veg for. If you top them and veg them until they are bushy monsters, you will need less plants. If you are doing Sea Of Green and putting your plants in flower early, you can use smaller pots and really pack them in there.