ΔE 20.5, loose: different enough that you should pick on purpose. Brutal Brown is noticeably darker, much more saturated, cooler than Paratrooper Tan.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Brutal Brown is noticeably darker, much more saturated, cooler than Paratrooper Tan.
The same difference applies the other way round: Paratrooper Tan is noticeably lighter, much 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 Paratrooper Tan on the colour wheel See Brutal Brown on the colour wheel
All matches: Paratrooper Tan equivalents · Brutal Brown equivalents