Actuator-disk models (ADMs) are widely used in wind-farm simulations, yet their ability to reproduce power and thrust fluctuations relative to actuator-line models (ALMs) has not been validated. Using JHTDB-Wind simulation data, we compare ADM and ALM turbine-response statistics under three atmospheric conditions within a diurnal cycle. ADM power and thrust are reconstructed from disk-averaged velocity and evaluated using time series, power spectra, alongside fluctuation and increment distributions. Results show that ADM captures temporal, spectral, and statistical behavior of the ALM at timescales slower than the rotor frequency. Results support ADM as an efficient tool for predicting turbine-response variability in large wind-farm simulations.