  We examine the robustness of collider phenomenology predictions for a dark
sector scenario with QCD-like properties. Pair production of dark quarks at the
LHC can result in a wide variety of signatures, depending on the details of the
new physics model. A particularly challenging signal results when prompt
production induces a parton shower that yields a high multiplicity of
collimated dark hadrons with subsequent decays to Standard Model hadrons. The
final states contain jets whose substructure encodes their non-QCD origin. This
is a relatively subtle signature of strongly coupled beyond the Standard Model
dynamics, and thus it is crucial that analyses incorporate systematic errors to
account for the approximations that are being made when modeling the signal. We
estimate theoretical uncertainties for a canonical substructure observable
designed to be sensitive to the gauge structure of the underlying object, the
two-point energy correlator $e_2^{(\beta)}$, by computing envelopes between
resummed analytic distributions and numerical results from Pythia. We explore
the separability against the QCD background as the confinement scale, number of
colors, number of flavors, and dark quark masses are varied. Additionally, we
investigate the uncertainties inherent to modeling dark sector hadronization.
Simple estimates are provided that quantify one's ability to distinguish these
dark sector jets from the overwhelming QCD background. Such a search would
benefit from theory advances to improve the predictions, and the increase in
statistics using the data to be collected at the high luminosity LHC.
