get more light to my plant

[tommy1984]

Hey guys, I have one plant particular (spontainca) that was toped at about 12 inches and grew into a 5ft tall and 8 ft wide bush (big and round like a ball) and I dont think its getting the light into it that it should be, the other one next to it that was also toped but grew 2 main tops is abput 7 ft tall and 4 ft wide but it is more open and can get more light into it. the one that is more open is WAYYY ahead of the other one as far as budding goes so that is why I dont think the bush is gatting enough light into it. I already tried to pull the 2 main shoots apart and tie them down to allow light to get in but the stalk where it y started to split, Im wondering if I can go in with scissors and go to town on the fan leaves or will that shock her and put her even father behind?