ΔE 13.4, fair: the same colour family, but not a straight swap. Iron Fist is noticeably darker than Plate Mail Metal.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Iron Fist is noticeably darker than Plate Mail Metal.
The same difference applies the other way round: Plate Mail Metal is noticeably lighter.
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 Plate Mail Metal on the colour wheel See Iron Fist on the colour wheel
All matches: Plate Mail Metal equivalents · Iron Fist equivalents