Comment was a mistake
So you CAN save your game in Panzer Paladin outside of Steam? That would be fantastic.
Then you just have the GOG version. No, because "replacing the Steam version with the GOG version" does not count as a patch.
The requirements in the wiki make it sound using a DRM free exe created by the devs would be ok, actually.
But if the user who's keeping that wiki (I think it's pedrovay2003?) could confirm, it'd be great.
The wiki page is generally referring to a .exe file that comes from an update file or something like that provided by the devs; replacing the files from one store's version with another isn't really the same thing, you might as well just buy it from the DRM-free store at that point.