ΔE 24.8, loose: different enough that you should pick on purpose. Ruby Red is noticeably darker, cooler than Overlord Brass.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 25). Ruby Red is noticeably darker, cooler than Overlord Brass.
The same difference applies the other way round: Overlord Brass 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 Overlord Brass on the colour wheel See Ruby Red on the colour wheel
All matches: Overlord Brass equivalents · Ruby Red equivalents