Left panel: cumulative distributions of Symphony subhalos’ most recent (solid, thick lines) and first (thin, dotted–dashed lines) accretion scale factors into any larger halo, stacked over all subhalos from each suite with M _sub/M _host > 2.7 × 10⁻⁴. Top ticks indicate lookback time assuming the cosmological parameters for our LMC, Milky Way, and Group suites. Right panel: same as the left panel, but with accretion scale factors normalized by the half-mass scale factor of each Symphony host. The legend indicates the mean half-mass scale factors for the LMC (pink), Milky Way (blue), Group (green), L-Cluster (gold), and Cluster (red) suites (see Table 1).