ΔE 10.7, fair: the same colour family, but not a straight swap. Six Shooter is a little lighter than Iron Warriors.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Six Shooter is a little lighter than Iron Warriors.
The same difference applies the other way round: Iron Warriors is a little darker.
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 Iron Warriors on the colour wheel See Six Shooter on the colour wheel
All matches: Iron Warriors equivalents · Six Shooter equivalents