... believe there were particular makers/models designed for these operatives and in reality also used by them in certain deployments at certain times...
covert para/mil individuals obviously carried actual knives.
ww2 saw numerous hidden last ditch stuff revolving around singularly built offensive capability.
www.thesun.co.uk/news/3984839/world-war-two-spies-gadget-weapons-real-james-bond/amp/
there was even that soe escape pliertool...
www.thesun.co.uk/news/2805353/secret-weapons-carried-by-ww2-spies-including-a-garotte-dagger-disguised-as-a-badge-and-a-poison-key-emerge-after-70-years/amp/
but way i see it,
anybody can confidently play
spy operative with the humble sak.