Adiabatic shear failure is a common failure mechanism in metals subjected to high loading rates. However, despite a large number of studies of adiabatic shear failure in heterogeneous materials, very few works have acknowledged the importance of phase continuity and associated plastic anisotropy (in some cases) on the onset of shear bands and their growth. Here, we present a systematic analysis using a model dual-phase material. Due to the lack of experimentally available data as to the evolution of the yield surface anisotropy with strain rate, several assumptions are made based on scarce experimental points found in the literature as well as experiments conducted in our lab on several lightweight alloys. We demonstrate that the yield surface anisotropy evolution with the strain rate as well as the resulting anisotropic heat dissipation will play a role in the onset and growth of adiabatic shear bands over a range of strain rates. Furthermore, the phase continuity and fraction, are found to control the evolution of shear bands by imposing barriers for shear band propagation.