A 50 50 mix of ffof soil and happy frog with earth worm casting under Mars hydro 300 watt light on 50% power hung 18 to 20 inches away the light on the side is just suplamentl I through in
It's just generic variation. The way the front 2 plants have there leaves angled upwards is a good sign of a healthy vigorous root system. The back 2 are slightly dropping because the root system is not as vigorous.
While it might look like the front 2 are going to better better plants you won't know until you flip and flower them. Sometimes the runts end up being the keepers.