1. A method for execution by one or more processing modules of one or more computing devices of a dispersed storage network (DSN), the method comprises: determining that storage of a set of storage units has been expanded; determining, for a plurality of sets of a desired number of encoded data slices, updated storage properties based on the storage expansion of the set of storage units, wherein a number of storage units in the set of storage units exceeds a number of encoded data slices of a set of the desired number of encoded data slices of the plurality of sets of the desired number of encoded data slices; and for each set of the desired number of encoded data slices of at least some of the plurality of sets of the desired number of encoded data slices: performing a scoring function using the updated storage properties to produce a per set storage resultant; identifying a sub set of storage units of the set of storage units for storing the set of the desired number of encoded data slices based on the per set storage resultant; and storing the set of the desired number of encoded data slices in the sub set of storage units.