ΔE 15.9, loose: different enough that you should pick on purpose. Mage Hunter Green is more muted, cooler than Steel Helmet Green.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Mage Hunter Green is more muted, cooler than Steel Helmet Green.
The same difference applies the other way round: Steel Helmet Green is more saturated, 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 Helmet Green on the colour wheel See Mage Hunter Green on the colour wheel
All matches: Steel Helmet Green equivalents · Mage Hunter Green equivalents