I like it - but as other have said, maybe a bot too high in the center. A good rule of thumb if you want to leave room for coral growth , is to go no higher than about half way up or just a little more.
It almost look like you could just take what you have and flip it on its side. With the currant base against the back glass, and the arch flat one sand bed protruding forward .
Then you could add a few small shelf pieces to raise up the form the the arch just a bit to keep the rock just at the sand level. this will create sand spaced below that a pistol shrimp could burro rounder and under.
This would transform this current rock work into two separate low towers or island on each side and a ring of small rock that coral could be mounted to. As it grows in this will create a natural habitat for the Fish