I just bought the game and I have to download 105GB compared to Steam which is around 70GB. Can the language archives be deleted without breaking the game? They eat up an enormous amount of drive space.

No, not from the installer download directly; there are no language selectable downloads.

You select the language when you install the game, and every other VO-archives are deleted after that (only a few MB dummy files are left behind). Which, personally, was annoying, because I had to install the game a second time to get the Japanese VO-files that I wanted, in addition to the default English.