ΔE 35.5, loose: different enough that you should pick on purpose. Raw Sienna is noticeably lighter, much more saturated, warmer than Martian Ironcrust.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 35). Raw Sienna is noticeably lighter, much more saturated, warmer than Martian Ironcrust.
The same difference applies the other way round: Martian Ironcrust is noticeably darker, much 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 Martian Ironcrust on the colour wheel See Raw Sienna on the colour wheel
All matches: Martian Ironcrust equivalents · Raw Sienna equivalents