ΔE 18.6, loose: different enough that you should pick on purpose. Traitor Green is a little lighter, much more saturated, cooler than Bastion Grey.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Traitor Green is a little lighter, much more saturated, cooler than Bastion Grey.
The same difference applies the other way round: Bastion Grey is a little darker, much more muted, 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 Bastion Grey on the colour wheel See Traitor Green on the colour wheel
All matches: Bastion Grey equivalents · Traitor Green equivalents