ΔE 5.3, very close: most people won’t see a difference side by side. Battleship Grey is cooler than Whale Grey. They are different kinds of paint: AMMO by Mig Whale Grey is an opaque base/layer paint and Army Painter Battleship Grey is a one-coat contrast-style paint, so they won’t behave the same on the model even where the colour is close.
Yes, for most jobs. Very close match (ΔE 5). Battleship Grey is cooler than Whale Grey. They are different kinds of paint.
The same difference applies the other way round: Whale Grey is 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 Whale Grey on the colour wheel See Battleship Grey on the colour wheel
All matches: Whale Grey equivalents · Battleship Grey equivalents