As is well known in the literature, an infinite linear (chain-like) charge distribution promotes a strong association between oppositely charged ions and the chain, known as counterion condensation. This effect arises from the cylindrical symmetry of the charge distribution and restricts the number of counterions that, for instance, contribute to the osmotic pressure. As discussed in our previous publication, 6 the linear-like charge distribution of the backbones in the simulations (locally) favors counterion condensation. Furthermore, the crosslinkers create regions of higher monomer density concentration, which can lead to higher local charge density, inducing strong counterion correlations. These phenomena are not present in the theoretical model, since we are considering a homogeneous spherical charge distribution for representing the microgel. In the theoretical model, we introduce this effect by effectively reducing the number of charges in the system, Z max,a , and we fit it with the constraint to be smaller than the Z max,a from the simulations. Regarding the determination of the collapsed volume, in an implicit-solvent coarse-grained simulation, the volume of the solvent element is not defined, which results in a problem when defining the microgel collapse radius a 0 in terms of the number of monomers or the number of segments. 6,40,41 Therefore, we take a 0 as a fitting parameter as well. We then obtain the theoretical predictions by fitting the reference collapsed volume via a 0 and the backbone charge Z max,a , such that the theory matches the simulation results of the swelling ratio α and the net charge Z net . Regarding the choice of the Flory χ parameter within the theory, we take χ = 0.1 to represent a polymer under good solvent conditions. This mimics the simulations, where the polymer segments have only excluded volume interaction. We further note that the exact numerical value of the parameter does not have a strong influence on the swelling behavior in the explored parameter ranges, leading only to minor differences.