ΔE 19.1, loose: different enough that you should pick on purpose. Gorgon Brown is noticeably lighter, cooler than Bestial Brown.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Gorgon Brown is noticeably lighter, cooler than Bestial Brown.
The same difference applies the other way round: Bestial Brown is noticeably darker, 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 Bestial Brown on the colour wheel See Gorgon Brown on the colour wheel
All matches: Bestial Brown equivalents · Gorgon Brown equivalents