ΔE 22.5, loose: different enough that you should pick on purpose. Rotten Flesh is a little lighter, much more saturated, cooler than Werewolf Brown.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 22). Rotten Flesh is a little lighter, much more saturated, cooler than Werewolf Brown.
The same difference applies the other way round: Werewolf Brown is a little darker, 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 Werewolf Brown on the colour wheel See Rotten Flesh on the colour wheel
All matches: Werewolf Brown equivalents · Rotten Flesh equivalents