The above picture is of all three hills. The top hill is SL 1 Tear Drop Hill and measures roughly 7" x 9". The right one is labeled as SL 11 and measures 5" x 8" although there is not a hill labeled as such on their website. The bottom one is RH 14 Rough Hill and measures 4.5" x 6". The rise is less than 0.5".
Here is the tear shaped hill from above. I think this one will also work as soft sand.
Tear shaped hill with a battle group of Egyptian Close Fighters marching across.
SL 11 Hill from above. This one will also work as soft sand.
SL 11 with the Egyptian foot marching across.
Here is RH 14 with the Egyptians marching across one of the rock outcroppings.