ΔE 10.9, fair: the same colour family, but not a straight swap. Sand Brown is more saturated, cooler than Bullwhack Brown.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Sand Brown is more saturated, cooler than Bullwhack Brown.
The same difference applies the other way round: Bullwhack Brown is more muted, warmer.
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 Bullwhack Brown on the colour wheel See Sand Brown on the colour wheel
All matches: Bullwhack Brown equivalents · Sand Brown equivalents