This research develops control strategies and provides guidelines for harmoniously operating distributed multiple Energy Storage System (ESS) for frequency regulation considering their respective State Of Charge (SOC). It proposes a droop control technique to dynamically allocate functional roles of multiple ESSs based on their SOC and ramping capabilities for stabilizing the grid frequency. ESSs autonomously maintain their SOC, securing the energy for future grid supporting services. This method helps ensure system integrity and improve robustness against unforeseen disturbances including highly variable renewable energy. Rigorous simulation studies demonstrate the applicability and effectiveness of the proposed droop control technique using PSCAD/EMTDC.