Just starting this, need some advice

I have a 9m2 room for growing and 4 600w light systems with both HPS and MH lamps. I'm planning to do a soil grow, how many plants do you guys think I should put under these lights? Should I SCROG? Would love some advice. Thanks in advance .)

I would say 2 per light depending on the size of the plants, 2 medium sized or maybe 3 smaller ones.

consider working space too. I use a meter to determine my sweet spots, they're cheap on amazon.
every grow bible lists lighting standards though as a good guideline.