ΔE 12.7, fair: the same colour family, but not a straight swap. Golfag Brown is much more muted than Leather Brown.
Can I use Golfag Brown instead of Leather Brown?
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Golfag Brown is much more muted than Leather Brown.
Can I use Leather Brown instead of Golfag Brown?
The same difference applies the other way round: Leather Brown is much more saturated.
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.