9 in a 200x200 , maybe 6 in the 150. So long as you provide ample energy you will find that the plant to will do a pretty good job of filling any space they are placed in. Might be able to squeeze 4 rows of 4 in a 200cm for 16, pots.
I recently done 4 automatics in a 120cmx120cm, because there was so much room the plant's where able to grow large and bountiful. Same yield as if I had done 12 smaller pots. Just much less space to grow.
When plants are packed too closely, they compete with one another for light, water, and nutrients. This can lead to a phenomenon known as "shade avoidance syndrome," where plants spend too much energy growing vertically to find light, rather than developing a full, robust structure.
By providing more space, each plant has ample room to grow outwards, develop a strong structure, and receive light across its entire foliage. The grower's goal is to manage the canopy to cover the entire available footprint evenly by the time flowering begins.
How much energy a plant can convert in a cycle and plant perception and available space the plant percieves will dictate how a plant grows. Don't be afraid to try different styles and see what works for you.
Less is always more when learning.