ΔE 6.7, close: similar, with a visible difference side by side. Parched Grass (Late) is a little lighter, warmer than Medium Drab.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Parched Grass (Late) is a little lighter, warmer than Medium Drab.
The same difference applies the other way round: Medium Drab is a little darker, 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 Medium Drab on the colour wheel See Parched Grass (Late) on the colour wheel
All matches: Medium Drab equivalents · Parched Grass (Late) equivalents