ΔE 13.9, fair: the same colour family, but not a straight swap. Burnt Umber is more muted than Overlord Olive.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Burnt Umber is more muted than Overlord Olive.
The same difference applies the other way round: Overlord Olive is more saturated.
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 Overlord Olive on the colour wheel See Burnt Umber on the colour wheel
All matches: Overlord Olive equivalents · Burnt Umber equivalents