Forecast errors on cosmological parameters for three n(z): with wide redshift bins and an outlier fraction of f_out = 0.1 or f_mout = 0.25 and with tight redshift bins. The results are shown for GCph+WL+XC, when marginalising (a) or not (b). We suppose a circular 15 000 deg² survey in the three cases. Top: relative error as a percentage for each cosmological parameter. The filled coloured bars represent the constraints obtained with the psky derivation using the wide n(z) with f_out = 0.1 (blue) or f_out = 0.25 (orange) and the tight n(z) (green). The hatched empty bars are the ones obtained in the fsky approximation. Bottom: relative difference between the fsky and the psky standard deviation for each galaxy distribution.