ΔE 9.7, close: similar, with a visible difference side by side. Ancestral Blue is a little darker, more saturated, warmer than Battleship Grey.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). Ancestral Blue is a little darker, more saturated, warmer than Battleship Grey.
The same difference applies the other way round: Battleship Grey is a little lighter, more muted, 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 Battleship Grey on the colour wheel See Ancestral Blue on the colour wheel
All matches: Battleship Grey equivalents · Ancestral Blue equivalents