*Disclaimer* The author is not an aquascaper.
...but I do know the theory behind it. The principle is to have the eyes follow a pattern of symmetry, beginning in the center and then flowing easily toward the sides and top of the tank.
Hornwort as a center piece plant doesn't work well IMO. You'd get better results by moving either your java fern rock or your driftwood to the center. Place a nice tall plant behind it and surround it with sloping level of plants, the short stems closer to the wood and the larger ones climbing up until you reach the sides.
HTH.