ΔE 18.8, loose: different enough that you should pick on purpose. Brutal Brown is noticeably darker, more muted, cooler than Desert Skin.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Brutal Brown is noticeably darker, more muted, cooler than Desert Skin.
The same difference applies the other way round: Desert Skin is noticeably lighter, more saturated, 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 Desert Skin on the colour wheel See Brutal Brown on the colour wheel
All matches: Desert Skin equivalents · Brutal Brown equivalents