ΔE 12.4, fair: the same colour family, but not a straight swap. Iron Warriors is noticeably lighter, more saturated than Rough Iron.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Iron Warriors is noticeably lighter, more saturated than Rough Iron.
The same difference applies the other way round: Rough Iron is noticeably darker, 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 Rough Iron on the colour wheel See Iron Warriors on the colour wheel
All matches: Rough Iron equivalents · Iron Warriors equivalents