In this frontier article we highlight recent advances in subcomponent self-sorting in self-assembled metal-ligand cage complexes, with a focus on selective discrimination between ligands that contain highly similar metal-coordinating groups. Effects such as varying ligand length, coordination angle and backbone flexibility, as well as the introduction of secondary weak forces such as hydrogen bonds can be exploited to favor either narcissistic or social self-sorting. We highlight these creative solutions, and emphasize the challenges that remain in the development of functional self-assembled heterocomplexes.