ΔE 13.1, fair: the same colour family, but not a straight swap. Paladin Flesh is more muted, warmer than Ruddy Umber.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Paladin Flesh is more muted, warmer than Ruddy Umber.
The same difference applies the other way round: Ruddy Umber is more saturated, 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 Ruddy Umber on the colour wheel See Paladin Flesh on the colour wheel
All matches: Ruddy Umber equivalents · Paladin Flesh equivalents