It depends who used the format first. This kind of joke (finns and Russians) has been used for a very very long time but the specific format may be created with a warhammer joke.
That’s what I figure. Without knowing the whole entomology of the joke, it sounds sufficiently old and generic that I imagine some version has existed long before it was applied to warhamner.
Ok so apparently warhammer was first created in 1987 and there's a recorded version of this joke in a Sten novel, idk which one, the first of which was printed in 82. So it's probably safe to assume warhammer reused the format. Also if we assume the Finn one is referencing the winter war and the white death it could date back to around 1940
Edited to rephrase