Intrinsic energy resolution in γ-radiation detectors is limited by nonlinear quenching that varies as the second or third power of local excitation density. Using a numerical model for local light yield depending on measured quenching rates, kinetic order, and carrier mobilities, we employ Monte Carlo simulations of energy deposited at each local excitation density to calculate electron energy response that can be directly compared with Compton coincidence and K-dip experiments. Agreement is found for NaI:Tl and SrI2:Eu using thermalized carrier diffusion and linear quenched fraction deduced from total light yield. This lays the groundwork for testing refinements with recent hot-electron extensions of the model.