It seems like there could actually be a difference between them?

https://en.wikipedia.org/wiki/Dead_man_zone - is related to bush fires but seems like it could apply to a battlefield?

https://en.wikipedia.org/wiki/No_man%27s_land

Something more akin to actually being in "measure" or strike distance vs just contested territory in between?

Edit: Sibling comment I think clears it up https://en.wikipedia.org/wiki/Kill_zone