Help, need different setup as over crowding

I have a 90cm x 90 1.2m high indoor grow . I had four ten litre tubs under a 400w light in coco and air post .. All vented ect, setup is pro setup ... I had to lollipop my plants because it was such a small place the bottom was receiving little if no light.... So I was thinking is there away round this but not topping ! Or am I better to put 2 plants in a nft setup = plants get more light and more bud or 4 plants and risk the over crowding... Any advice or info greatful only my second grow so a newbie really

under a 400 i wouldnt do more than 2 plants

That's my point is 2 big plants better then 4 small ones

get yourself a ScROG screen and get it in there, train the plants into it then flip 12/12 the screen will allow the 400w light to cover the entire canopy better than if you let them grow normal. trim off any nodes that arent in the screen and next time remember thast they get big fast and only grow what you have space for.

Thank you that was very helpful cheers pal