Median number of accreted halos required to assemble the ICL_post. The lines indicate the median distribution (solid green for GADGET-X, dash-dotted magenta for GIZMO-SIMBA), while the shaded regions denote the 16th–84th percentiles. The halos are ordered starting from the one that contributes the most, and the values on the y-axis are the cumulative contribution of all previous halos, normalised by the ICL_post mass at z = 0. The horizontal lines indicate fractions of 0.5 and 0.8 on the y-axis, for reference.