ΔE 12.7, fair: the same colour family, but not a straight swap. Thornwood Green is a little lighter, more saturated, cooler than Steel Legion Drab.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Thornwood Green is a little lighter, more saturated, cooler than Steel Legion Drab.
The same difference applies the other way round: Steel Legion Drab is a little darker, 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 Steel Legion Drab on the colour wheel See Thornwood Green on the colour wheel
All matches: Steel Legion Drab equivalents · Thornwood Green equivalents