ΔE 4.2, very close: most people won’t see a difference side by side. Tiger Eye Brown is a little lighter than Rust. They are different kinds of paint: Army Painter Rust is an opaque base/layer paint and Green Stuff World Tiger Eye Brown is an ink, glaze or transparent 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 4). Tiger Eye Brown is a little lighter than Rust. They are different kinds of paint.
The same difference applies the other way round: Rust is a little darker.
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 Rust on the colour wheel See Tiger Eye Brown on the colour wheel
All matches: Rust equivalents · Tiger Eye Brown equivalents