ΔE 28.5, loose: different enough that you should pick on purpose. Copper Coin is noticeably darker, warmer than Auric Armour Gold.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 29). Copper Coin is noticeably darker, warmer than Auric Armour Gold.
The same difference applies the other way round: Auric Armour Gold is noticeably lighter, cooler.
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 Auric Armour Gold on the colour wheel See Copper Coin on the colour wheel
All matches: Auric Armour Gold equivalents · Copper Coin equivalents