ΔE 23.5, loose: different enough that you should pick on purpose. Guilliman Flesh is noticeably lighter, much more muted, warmer than Aged Hide.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 24). Guilliman Flesh is noticeably lighter, much more muted, warmer than Aged Hide.
The same difference applies the other way round: Aged Hide is noticeably darker, much more saturated, cooler.
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 Aged Hide on the colour wheel See Guilliman Flesh on the colour wheel
All matches: Aged Hide equivalents · Guilliman Flesh equivalents