ΔE 20.5, loose: different enough that you should pick on purpose. Tooth and Nails is noticeably lighter, more saturated than Longbeard Grey.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Tooth and Nails is noticeably lighter, more saturated than Longbeard Grey.
The same difference applies the other way round: Longbeard Grey is noticeably darker, more muted.
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 Longbeard Grey on the colour wheel See Tooth and Nails on the colour wheel
All matches: Longbeard Grey equivalents · Tooth and Nails equivalents