ΔE 21.7, loose: different enough that you should pick on purpose. Sand Grey is noticeably darker, much more saturated than White Scar.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 22). Sand Grey is noticeably darker, much more saturated than White Scar.
The same difference applies the other way round: White Scar is noticeably lighter, much more muted.
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 White Scar on the colour wheel See Sand Grey on the colour wheel
All matches: White Scar equivalents · Sand Grey equivalents