ΔE 14.6, fair: the same colour family, but not a straight swap. Arcane Gold is noticeably darker, cooler than Ancient Bronze.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Arcane Gold is noticeably darker, cooler than Ancient Bronze.
The same difference applies the other way round: Ancient Bronze is noticeably lighter, warmer.
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 Ancient Bronze on the colour wheel See Arcane Gold on the colour wheel
All matches: Ancient Bronze equivalents · Arcane Gold equivalents