ΔE 31.0, loose: different enough that you should pick on purpose. Gladius Bronze is noticeably lighter than Hashut Copper.
Can I use Gladius Bronze instead of Hashut Copper?
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 31). Gladius Bronze is noticeably lighter than Hashut Copper.
Can I use Hashut Copper instead of Gladius Bronze?
The same difference applies the other way round: Hashut Copper is noticeably 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.