  Multiorbital Hubbard models host strongly correlated 'Hund's metals' even for
interactions much stronger than the bandwidth. We characterize this
interaction-resilient metal as a mixed-valence state. In particular it can be
pictured as a bridge between two strongly correlated insulators: a high-spin
Mott insulator and a charge-disproportionated insulator which is stabilized by
a very large Hund's coupling. This picture is confirmed comparing models with
negative and positive Hund's coupling for different fillings. Our results
provide a characterization of the Hund's metal state and connect its presence
with charge disproportionation, which has indeed been observed in chromates and
proposed to play a role in iron-based superconductors.
