ΔE 15.0, loose: different enough that you should pick on purpose. Brutal Brown is more saturated, cooler than Sylvaneth Bark.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Brutal Brown is more saturated, cooler than Sylvaneth Bark.
The same difference applies the other way round: Sylvaneth Bark 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 Sylvaneth Bark on the colour wheel See Brutal Brown on the colour wheel
All matches: Sylvaneth Bark equivalents · Brutal Brown equivalents