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