ΔE 13.7, fair: the same colour family, but not a straight swap. Speed Metal is noticeably lighter, more saturated than Broadsword Silver.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Speed Metal is noticeably lighter, more saturated than Broadsword Silver.
The same difference applies the other way round: Broadsword Silver is noticeably darker, 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 Broadsword Silver on the colour wheel See Speed Metal on the colour wheel
All matches: Broadsword Silver equivalents · Speed Metal equivalents