Summary overview of the median metallicity values within GSS, NE and W shelves of the model to be compared with spectroscopic metallicity estimates from the DESI survey, Escala et al. 2020 (for the GSS; labelled as E+20 in the figure), and Escala et al. (2022) (for the NE shelf; labelled as E+22 in the figure). For each substructure, we report the median values from their components identified in the simulations by DBSCAN and labelled as C1, C2, etc. The error bars denote the standard deviation both for the data distributions and the distributions obtained from the simulation model.