ΔE 11.4, fair: the same colour family, but not a straight swap. Catachan Flesh is noticeably lighter than Rawhide Brown.
Can I use Catachan Flesh instead of Rawhide Brown?
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Catachan Flesh is noticeably lighter than Rawhide Brown.
Can I use Rawhide Brown instead of Catachan Flesh?
The same difference applies the other way round: Rawhide Brown is noticeably darker.
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.