Wow that's big. I got a 40cm x 40cm x 80cm tent. That's pretty small. Would you say one big pot is better than 4 smaller pots then? Would I get bigger yield off 1 big plant?
I wouldn't try to put more than one plant in there. That is just simply not enough space for more than 1 plant.(barely enough for 1 plant)
What I would do-
Find a dark walled container that is 40x40 wide and not too tall(1 foot). That will max out your medium size. The bigger your medium the more roots you have, the more roots you have the more plant the roots can support, the more plant the roots can support the more bud the plant can grow. So your medium size will directly influence the size of your harvest
Grow just 1 plant and let it get to 1/3 of the final height that you will be able to grow to.
When it becomes 1/3 your final height(remember to account for the height of the pot, the space taken for the lights, and the space needed between the bulbs and the plant... so you won't have much space for the plant with only 80cm!) cut the top shoot off and let the plant veg for another week or more or until the top branches start to grow out.
So you will have topped the plant at 1/3 of the final height allowance of your space, and now you will veg it until it reaches 1/2 the final height allowance for your space. That will mean the shoots the grew out to replace the top you removed will be sizeable enough to each develope a good sized bud. The benefits to this stratagy are threefold
1. you can veg your plant longer, meaning more roots will grow(and as I said more roots=more bud)
2. You can turn the 1 top bud into 2 or 4(that will depend on how the plant responds, it may grow 2 or 4 main shoots after topping)
3. Your plant will have a narrow profile that prevents it from pressing fan leaves/budsites up against the sides of the tent.
If you grow 4 plants you'll have to find some old japaneese bonsai master to teach you how to grow midget plants