ΔE 8.6, close: similar, with a visible difference side by side. Leather Brown is more muted, cooler than Earth Clay.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Leather Brown is more muted, cooler than Earth Clay.
The same difference applies the other way round: Earth Clay is more saturated, warmer.
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 Earth Clay on the colour wheel See Leather Brown on the colour wheel
All matches: Earth Clay equivalents · Leather Brown equivalents