Stellar mass distributions of progenitor galaxies at z_ini = 3 contributing at least 5% to the final stellar mass of the four top-ranked galaxies at z_fin = 0, shown separately by group class. In each panel, transparent-shaded histograms are overlaid to show the stellar mass distributions of the corresponding top-ranked galaxies at the end of the simulations. The initial mass distributions of these galaxies are provided in Fig. 1. The coding of colours and line styles of group classes is the same as in Fig. 1.