ΔE 27.1, loose: different enough that you should pick on purpose. Army Green is much more muted, warmer than Leafy Green.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 27). Army Green is much more muted, warmer than Leafy Green.
The same difference applies the other way round: Leafy Green is much 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 Leafy Green on the colour wheel See Army Green on the colour wheel
All matches: Leafy Green equivalents · Army Green equivalents