This study explores whether simulator-derived workload metrics can indicate differences in performance between ATC student cohorts. A standardized radar simulation was conducted with 14 participants (7 fourth-year, 7 fifth-year). Workload was modeled using event-based HUM-SIM principles and combined with instructor evaluation. The results suggest higher workload exposure, longer critical states, and greater deviation from the planned scenario in less experienced students. Differences appear not only in workload magnitude but in its temporal regulation. These findings indicate that workload-informed metrics may support objective performance assessment in simulator-based training, although further validation on larger datasets is required.