Overall it is shown that models 1 and 3 can explain the experimental Mössbauer signals of the active sites in FeNC catalysts considering the catalytic cycle for the ORR, whereas model 2 does not provide a consistent picture. It is further evident that models 1 and 3 differ in their response towards axial ligands. For instance, model 1 generally exhibits a downfield shift of the isomer shift, while model 3 exhibits negligible to upfield shift of the isomer shift in the presence of axial oxygen ligands. Mössbauer experiments with precise ligand control, e.g. poisoning or inert-atmosphere-experiments, may be crucial in distinguishing the presence of either motifs in respective FeNCs.