Single free-layer Magnetic Tunnel Junctions (MTJs) with a perpendicular easy axis driven by spin currents have demonstrated fast, deterministic switching, non-volatility, and low-power memory capabilities when integrated with modern nanoelectronic devices. In this article, we numerically investigate sub-ns and field-free switching characteristics of a p-MTJ with a Synthetic Antiferromagnet (SAF) based free layer structure using sequential sub-ns current pulses of Spin Orbit Torque (SOT) and Spin Transfer Torque (STT). While the SOT pulse applied to one layer decreases the transition time by bringing the coupled layers into an in-plane configuration, the subsequent STT pulse on the system determines the switching direction. Various pulse protocols have been investigated for both SOT and STT current amplitude and pulse widths, while also considering the effect of the Reference Layer (RL). While significant regions of deterministic switching events are observed, limitations in SOT, STT parameters are further investigated in presence of thermal fluctuations.