ΔE 18.1, loose: different enough that you should pick on purpose. Deathclaw Brown is noticeably lighter, more saturated, warmer than Rust in Peace.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Deathclaw Brown is noticeably lighter, more saturated, warmer than Rust in Peace.
The same difference applies the other way round: Rust in Peace is noticeably darker, more muted, cooler.
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 Rust in Peace on the colour wheel See Deathclaw Brown on the colour wheel
All matches: Rust in Peace equivalents · Deathclaw Brown equivalents