We study ensembles of half-BPS bound states of fundamental strings and NS-fivebranes (NS5-F1 states) in the decoupling limit. We revisit a solution corresponding to an ensemble average of these bound states, and find that the appropriate duality frame for describing the near-source structure is the T-dual NS5-P frame in which the fivebranes are generically well-separated; this property results in the applicability of perturbative string theory. The geometry sourced by the typical microstate is not close to that of the black hole that carries the same charges. When members of the ensemble spin with two fixed angular potentials about two orthogonal planes, we find that the ensemble average geometry has an ellipsoidal structure. This contrasts with ring structures obtained when fixing the angular momenta instead of the angular potentials; we trace this difference of ensembles to large fluctuations of the angular momentum in the ensemble of fixed angular potential.