ΔE 25.4, loose: different enough that you should pick on purpose. Graphite Grey is a little lighter, much more muted than Satchel Brown.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 25). Graphite Grey is a little lighter, much more muted than Satchel Brown.
The same difference applies the other way round: Satchel Brown is a little darker, much more saturated.
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 Satchel Brown on the colour wheel See Graphite Grey on the colour wheel
All matches: Satchel Brown equivalents · Graphite Grey equivalents