wILL THE STRONG SURVIVE?

I have about 9 out of 11 plants that I was growing in a 6" nurturing planter that I had just simply threw the seeds out the sacks into on a constant basis, mix up the dirt alittle by hand. Water on a constant basis, and out of alot of seeds and watering I had about 13 plants growing, well they grew to about any where from 4 nodes, the tallest having 8 nodes. However, they grew 2gether in the same 6" pot, and I trasferred them to a larger pot measuring 12" in diameter and 12" high with 3 holes and a large crack I placed in for extra water drainage, besides the 3 small holes inent for that same function. I placed them in the same way they were when they were in the 6"pot, closely together. But not too close, tho now, 9 have thus recovered succesfully from the transfer. Measuring them, the samllest having 4 nodes the tallest having 9 nodes. I have been told that I should move the plants to thier very own large pots (one each pot) or at the least, farther apart since i do now have alot of space now that they are in a bigger pot. However, I am worried that if I try that, I might actually kill the plants, since the roots must surely be entangled by now. So should I just let them grow the way they have been, and let the weaker ones eventually get "choke out" by the stronger ones. Will the weaker (younger,less nodes) even get choked out? I am a first timer and did this just throw 'em in and water them after a failed germination/transfer experiment. I have them set up on the floor with a simple 15 watt, 18" long flourecent light setup being held in the air by two nylon cords, tied over like a venation blind setup. Just in a simple closet that stays on 24/7. I water the plants about two or three times a day and mist the leaves from afar with a spray bottle that I fill with filtered water. The plants have continued to grow and only problem I have is wether to move the plants farther apart or to thier own large pot, and a minor case of fungus gnats. But if you have any pointers let me know.