This paper reports on the impact of UAV swarm density and heterogeneity on synthetic aperture DoA convergence. The synthetic aperture is derived from the displacement of distributed UAVs (agents) operating in a sparse volumetric swarm. Heterogeneity arises from the changing orientation of an agent's antenna and receiving pattern function as it swarms in the distributed cluster of agents. This alters the agents' antenna pattern function(s) over time and alters the convergence and overall performance properties of vector-space direction of arrival techniques. The goal of this work is to evaluate the impact of the swarm density and orientation in this framework and study the convergence and error using this technique under different SNR conditions using the MUSIC algorithm. Simulation and measurements for up to sixteen elements on a thirty-Two-location test platform are provided and comparisons are made to benchmark their performance with theoretical expectations.