When performing core loading pattern design in fast spectrum reactors, it is often assumed that the larger neutron mean free path in fast reactors makes the core loading pattern less significant than in thermal reactors. Due to this assumption, the literature often includes homogeneous core designs for liquid-metal-cooled fast reactors (LMFRs). In this paper, heterogeneous loading patterns are investigated using modern LMFR multiphysics analysis. It was found that the figures of merit (FOMs) used to design cores are very sensitive to the core loading pattern, and better core designs (measured by the FOM) can be obtained from heterogeneous designs.