FoM as a function of the number of bins for GC_ph (solid) and GC_ph + GGL (dashed), and for bins with the same redshift width (blue) and with the same number of objects (red). The redshift width of the bins when they have the same width is shown in the top x axis. The FoMs are normalized to the FoM at ten bins, FoM_ref, which corresponds to the specifications for the number of bins used to compute the forecasts in EC20 and denoted by a vertical-dashed line. A vertical-dotted line shows the 13 bins used as our fiducial choice.