Your two islands are in the right spot 1/3 x 1/3 the rock at your overflow???????????
A thought....
If you want to add depth on each island divide the tops into 2 half's....on the island to the left have the point of the back half reach 2/3rds DT total height....The front half 1/3 total DT height but not in line with each other. Do the same with the other island just backwards so when viewing from either side you get depth. Also add flowing S, U, C, shapes to base rocks supporting islands it allows eyes to flow across and in and out of DT rockwork.