ΔE 13.9, fair: the same colour family, but not a straight swap. Dark Mud is noticeably darker, more saturated, cooler than Ammo Pouch Brown.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Dark Mud is noticeably darker, more saturated, cooler than Ammo Pouch Brown.
The same difference applies the other way round: Ammo Pouch Brown is noticeably lighter, more muted, 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 Ammo Pouch Brown on the colour wheel See Dark Mud on the colour wheel
All matches: Ammo Pouch Brown equivalents · Dark Mud equivalents