Upper panel: the difference d_FoM, defined in (47), as a function of the photo-z dispersion σ_ph, shown for ϵϵ correlations (dashed line), all correlations (black solid line), and the lensing only signal (grey solid line). Throughout, nuisance parameters N_K = N_Z = 5 are used. These results are obtained for the standard set of parameters and N_zbin = 10. Lower panel: Same as above, but in terms of the ratio r_FoM, given in (46).