ΔE 10.9, fair: the same colour family, but not a straight swap. Brigandine Brown is a little lighter than 3B AU/ZB AU.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Brigandine Brown is a little lighter than 3B AU/ZB AU.
The same difference applies the other way round: 3B AU/ZB AU is a little darker.
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 3B AU/ZB AU on the colour wheel See Brigandine Brown on the colour wheel
All matches: 3B AU/ZB AU equivalents · Brigandine Brown equivalents