Military Shader vs Orc Flesh Wash

How close are they?

ΔE 29.3, loose: different enough that you should pick on purpose. Orc Flesh Wash is noticeably lighter, cooler than Military Shader.

Can I use Orc Flesh Wash instead of Military Shader?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 29). Orc Flesh Wash is noticeably lighter, cooler than Military Shader.

Can I use Military Shader instead of Orc Flesh Wash?

The same difference applies the other way round: Military Shader is noticeably darker, 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.