it's much simpler – you need to follow the installation order:
1) install The Shadow of Death (recommended) or Platinum Edition, or a previous version of WoG
2) when installing The Shadow of Death, the directory is selected automatically (at least, that's how it works for me), therefore, move all the contents of the Heroes folder to a folder whose path consists ENTIRELY of Latin letters, for example, C:\Games\Heroes III WoG
3) Extract all files from the allion1 archive into the allion1 folder, where a file named wog358f.part01 with the WoG icon and files with the RAR extension will appear.
4) Run wog358f.part01, and then confirm the path for extracting the files (by default, this is the WogInstall folder, which will be created in the allion1 folder).
5) After unpacking, a folder named WogInstall will appear, which should be moved to the folder C:\Games\Heroes III WoG.
6) Run the install file from the WogInstall folder – after a while, a language selection menu will appear, followed by a window with the inscription "welcome" – click the next button.
A window with the "list of found components" and 3 buttons: change patch install and cancel will appear.
7) Click change patch, and in the window that opens, specify the path to the folder with the game (C:\Games\Heroes III WoG) and click ok.
8) After clicking the ok button, the "list of found components" window will appear again – click install.
After the WoG installation process, you will, of course, need to install the Russian language pack, for this:
1) Extract 3 files with the wog extension from the rubeta358f archive.
2) Move these files to the directory C:\Games\Heroes III WoG\update.
3) Run the H3Wupd.exe file in the folder C:\Games\Heroes III WoG.
Then, proceed as with the WoG installation.