ΔE 20.7, loose: different enough that you should pick on purpose. Ground Brown is a little darker, more saturated, warmer than Uniform Grey.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Ground Brown is a little darker, more saturated, warmer than Uniform Grey.
The same difference applies the other way round: Uniform Grey is a little lighter, more muted, 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 Uniform Grey on the colour wheel See Ground Brown on the colour wheel
All matches: Uniform Grey equivalents · Ground Brown equivalents