I'm not sure what you have underneath that rock, but heavy rocks that are unsupported below can sink, cause the equivalent of a mini-landslide that flattens out the slope, as you make adjustments, planting etc. Perhaps can consider putting supports below the stones or substrate supports?
It also allow smaller stones to stand taller... something like this
This allow very steep slopes even with heavy rock
In this tank, the large stone is 10+ kg and is raised 5 inches off the base. In this case, substrates supports would still slide, and egg-crate construction like the one above or using more stones as a base is the only way to get stability. With a support base, it makes full use of the stone as less of it needs to be buried in the substrate for stability sake.
I think having a more dramatic slope can be interesting with regards to your scape
I'm not sure of your plant selection; if you're doing a more purist iwagumi style with mostly carpets, then having more space in the front works. However, if you're using anything other than low carpets, they may quickly over-grow the smaller size stones. In this case, moving the smaller size stones forward more may make them more visible.
The 3 stones from the right as a bit fragmented from the group, but not strong enough to stand by their own. Having them on the same horizontal plane can make things a bit too flat/stable. Perhaps something more to the front or back might be better. Not sure if a split grouping would work; maybe can have a path or ravine between them ha