  We study and classify $SU(5)$-GUT completions of accidental composite dark
matter models. These theories postulate new vectorlike confining dark color
dynamics and give an accidentally stable baryonic dark matter candidate. In
realistic theories, dark fermion $SU(5)$ irreps split into light dark quarks,
whose bound states include the dark matter, and their much heavier GUT
partners. A simple analysis shows that such a mass hierarchy requires a fine
tuning of parameters and thus implies a naturalness problem. We select theories
requiring that all dangerous metastable states decay before the onset of
nucleosynthesis through higher-dimensional operators generated at the GUT scale
or at the mass scale of dark quark GUT partners. Demanding Standard Model gauge
coupling unification puts severe constraints on the landscape of viable
theories. Under the assumption of an approximately degenerate spectrum of dark
quark GUT partners, we find that only one model gives precision unification.
