Under the collective limit (N ≫ 1) and the Markovian limit (t → ∞), the NE-FGR formalism reduces to the well-known E-FGR rate expression (frequency-domain formalism in Eq. 30a). Compared to the NE-FGR expressions, these E-FGR rate expressions have the same scaling relation in terms of N . The difference between the time-independent and time-dependent rate theory is tested via the application of E-FGR and NE-FGR to an experimentally relevant model system. As expected, the time-dependent NE-FGR rates deviate from the E-FGR rate transiently before converging to the E-FGR rate constant on similar timescales for all six population transfers. The significance of this deviation is different for each population transfer process and is stronger for the energetically unfavorable population transitions. In the collective limit N → ∞, the population dynamics is dominated by transfer from the polaritons to the dark states, which scales favorably with N . Therefore, LP → D rate shows the most significant deviation from the equilibrium rate in an experimentally relevant setting.