ΔE 28.6, loose: different enough that you should pick on purpose. Dwarf Shield is noticeably darker, much more saturated than Iron Warriors.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 29). Dwarf Shield is noticeably darker, much more saturated than Iron Warriors.
The same difference applies the other way round: Iron Warriors is noticeably 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 Iron Warriors on the colour wheel See Dwarf Shield on the colour wheel
All matches: Iron Warriors equivalents · Dwarf Shield equivalents