A key element in the design of a coaxial generator system is the simplicity of the geometry. The clean cylindrical geometry allows us a reasonable chance at modeling RANCHER0 performance using our 1D and 2D MHD modeling codes. The results of numerical simulations have been compare to several tests of the RANCHER0 system in a variety of configurations. Recent comparisons of 1D calculations with the REOT-2 data have been extremely good and suggest that the generator is behaving in a very 1D like nature until reaching 90-95% of peak current. Differences between calculated current and measured performance during the last 3 mm (out of 70 mm) of flux compression may be a consequence of either the EOS for SF6, 2D effects, or both. This study will examine the existing models and attempt to provide a robust integrated model which can then be used to drive design studies, pre- and post-shot analysis, and predict performance parameters for slight variations of the base design of RANCHERO.