This research performs a detailed comparison of fundamental frequency positive sequence (RMS) and electromagnetic transient (EMT) based simulations of a two-area four-machine system with power-electronics based non-synchronous generation (NSG). The RMS based simulations are performed in PowerFactory and the equivalent EMT simulations are performed in PSCAD. Parity between the two-area four-machine model constructed in PSCAD and PowerFactory is rigorously established. The default fully rated wind converter model from PowerFactory with fault ride through is adopted in PSCAD, utilizing the same control strategy. The transient stability of the two-area four-machine model with NSG in PSCAD and PowerFactory is evaluated with respect to one another. Specific RMS modeling limitations are also discussed in this paper.