1. A method comprises: identifying a memory loading mismatch between a first memory device and a second memory device of a dispersed storage (DS) unit, wherein the first memory device is assigned a first range of slice names and the second memory device is assigned a second range of slice names; determining an estimated impact to reduce the memory loading mismatch; when the estimated impact compares favorably to an impact threshold, modifying the first and second ranges of slices names to produce a first modified range of slice names for the first memory device and a second modified range of slice names for the second memory device based on the memory loading mismatch; and transferring one or more encoded data slices between the first and second memory devices in accordance with the first and second modified ranges of slice names.