hey,

if they are already arranged close together, and re-arranging them will be more trouble than you're willing to overcome, then yes as far as i understand you can trim areas underneath that aren't getting enough light, since they won't produce buds anyway and will only hoard vital nutrients and allocate energy into leaf production, which you don't want in a SOG setup. if you want to use the 'sea of green' method you better kick them into flower early, while the plants are between 6-12 inches tall. sounds like you're aiming in that direction, so don't let them grow too big. 9"-12" square inches per plant will concentrate cola growth at the top centre of the plant, all other areas being negligible. good luck.

P.S. if you want more helpful replies you should probably take a minute to read your post and ensure your grammar is half decent