From the theories, a slightly different behavior of Z net is predicted. Both theories describe the increase of |Z net | with increasing ζ with a larger prediction of |Z net | from Gaussian model. However, the saturation that is observed in simulations is not present in the theoretical cases. In order to understand such discrepancies, we have calculated Z net from PB theory, but accounting for the microgel sizes obtained from the simulations. These results are shown in Fig. (a) for fitting factor φ coll = 0.22, which produces the best fitting of the swelling ratio R g /R g (Z = 0), and in Fig. ) for fitting factor φ coll = 0.05, which produces the best fittings of the absolute microgel sizes a eq . The figures show that accounting for the correct microgel size from the simulations in PB theory does not correctly reproduce Z net behavior at large ζ either. We observe indeed that the qualitative shape of the swelling models and the PB theory with the correct sizes are alike, with the clear overestimation of |Z net | at large microgel sizes. That allows us to infer that the discrepancies lay on the differences in spatial charge densities between the theoretical models and the simulation model, and on the treatment of the correlations. Differently from the assumed homogeneous charge distribution of the theoretical PB framework, the chain-like arrangement of the charges in the simulation model favors Manning condensation for ionization degrees ζ ≥ 0.5, since we take λ B = 2σ . The strong counterion condensation leads to a larger presence of counterions inside the microgel, diminishing |Z net | and augmenting the screening inside the microgel, which results in a weaker swelling. This explains the strong overestimation of |Z net | as well as the tendency to an overestimation of the microgel size at large ionization degrees by the theoretical models. Moreover, the saturation of Z net agrees with the fact that Manning condensation induces a condensation of ions such that the Manning parameter Γ = 1, leading to a similar effective network charge density for ζ > 0.5. In conclusion, the slow growth in swelling ratio at large ionization degrees is strongly influenced not only by the finite extensibility of the polymer chains, but also by Manning condensation, specially at large N.