Comparison between the observed and the simulated σ_RM as a function of the projected distance from the cluster centre for the five radio galaxies analysed in this Section (in distance order: T1, T2, W2, W1, Group G). The black pentagons refer to the observed data, where the errors are computed as in Eq. (2). Coloured symbols represent the mean over five simulations of σ_RM extracted from each source. From higher to lower: blue (3.0 μG), light-blue (2.0 μG), purple (1.5 μG), and bordeaux (1.0 μG). Different shapes represent different MF power spectrum peaks. From higher to lower: square (280 kpc), triangle (140 kpc), and circle (70 kpc). Again, the simulated values are taken from the half-integration RM maps for the embedded sources, whereas for the background radio galaxies, they were taken from the total-integration maps. The associated error is computed as the sum in quadrature of Eq. (2) and the mean of the scatter of five simulations in the annulus in which the source is located. The σ_RM axis is in logarithmic scale for a better visualisation of the profile.