A large scale investigation into the effects of alloy layer disorder on emission in antimonide-based superlattices is reported. The potential utility of these systems in infrared (IR) optoelectronic technologies is reviewed and issues inhibiting their realization identified. The Ga0.7In0.3Sb alloy layer is modeled using both the conventional virtual crystal approximation and models which describe microscopic disorder, clustering, and atomistic relaxation. The structures have recently been fabricated for IR laser applications and we investigate the influence of the alloy description on the emission line shapes. For each superlattice we find that the emission linewidth and peak height is very sensitive to the microscopic details of the alloy potential. Comparing the various superlattice systems, which differ regarding the InAs layer widths, we find that their linewidth values (eV) are each of the same order of magnitude for a given population of excited carriers. While values show a strong dependence on the period, reflecting large differences in the interband transition probabilities, the relationship between linewidth and excited carrier population does not show a clear correlation with superlattice period. This article demonstrates quantitative links between microscopic disorder and the optical properties of strained-layer superlattices.