While pondering the strength of earth bags and suitability to carry a heavy load, I though that maybe pairing the concept of reinforced sand with earth bags and thought the large (
example 41 x 41 x 52 inches) bulk bags could be filled with tamped sand interspersed with window screen pieces that create a reinforced layer, something like every 8 inches. These bags typically can hold 1,000-1,200 lbs, so obviously they would need to be filled in place unless a small crane is available.
An ancillary idea involves placing rods at the intersection of each bag with a buried attachment on one end buried in the berm to act as a stabilizing “deadman” and the other end projecting from the bags onto which a facing could be attached.