ΔE 15.0, loose: different enough that you should pick on purpose. IDF/IAF Green is a little darker, much more saturated than Typhon Ash.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). IDF/IAF Green is a little darker, much more saturated than Typhon Ash.
The same difference applies the other way round: Typhon Ash is a little lighter, much more muted.
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 Typhon Ash on the colour wheel See IDF/IAF Green on the colour wheel
All matches: Typhon Ash equivalents · IDF/IAF Green equivalents