ΔE 12.3, fair: the same colour family, but not a straight swap. Our swatches for the two are almost the same. They are different kinds of paint: Army Painter Satchel Brown is a one-coat contrast-style paint and Golden Sepia is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). The swatches are almost the same. They are different kinds of paint.
The same difference applies the other way round.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Satchel Brown on the colour wheel See Sepia on the colour wheel
All matches: Satchel Brown equivalents · Sepia equivalents