For your first grow you def went all in....lol. I’m new to indoor, but I’d lower the light another foot and go ahead and group them together. No real reason to have them on all four corners. Switch to watering a 6-8†area around each plant daily of 8oz-ish. You’re drying out their roots and then overwatering them. I’m not sure the amount of heat your Mh light is putting out, I use LED. I do know soil tho. With the amount of vermiculite I see in your bags the water is just going straight down. Trust me, do what Canuck and I are saying and you’ll see a change in just a couple days. You may be a bit low on nitrogen too.
Good luckðŸ™ðŸ¼