Average metallicity and metallicity dispersion (the “error” bars) as a function of absolute magnitude for the four target satellites. Objects that have no dispersion measurement or only limits are plotted without an error bar, as for Horo II. The metallicities for the “other objects” are from Torrealba et al. (2016), Martin et al. (2007), Simon & Geha (2007), Simon et al. (2015, 2011, 2017), Koch et al. (2009), Carlin et al. (2009), Li et al. (2018a, 2017, 2018b), Kirby et al. (2015, 2013, 2017), Walker et al. (2016, 2009), Koposov et al. (2015b, 2018), Kim et al. (2016), Willman et al. (2011), Norris et al. (2010) and Longeard et al. (2018). The point at M_V = −5.3/[Fe/H] = −1.68 is Laevens 1/Crater I, which is probably a globular cluster.