What kind of look are you going for?
There’s a few different categories (or at least this is how I think of it):
1) The Miniature Landscape - appearance like a large reef shrunken down. Achieved by creating depth of field ie taller & larger elements in back with smaller shorter elements in front. Macro (back) > micro (front)
2) The Window - appearance like looking through a window underwater. Achieved by using relatively larger & similarly sized elements throughout the tank but important keep variety in shape of elements
3) The Abstract - appearance like whatever the hell you want. Would you find this look in nature? No. Do you get to play god and make your own rules? Yes! Achieved by breaking reality.
What you have going right now seems too uniform at least from your picture. I would introduce more variation in height of the structures from an aesthetic standpoint. From a reefing standpoint, more slope in structures would be nice for added coral real estate.