Found that game has no VO if choose English language (not a surprise, this was in item description). How can I combine eng text with Polish language?
Seems that steam version got Polish language pack as a separate dlc.

Came here for the same reason, can the Polish language pack be added to GOG as well?

I've managed to get English subtitles with Polish voiceover as a rudimentary solution until the official version arrives.

Here's what I did:
1. back up the Data folder of the English version
2. In your library, find Archolos and go to Manage installation - Configure
3. Select the Polish language. This will result in a download of approximately 4,2 GB
4. Replace some files in the downloaded Polish version with files from the English backup:
- KM_LocalizationEN.mod - rename to KM_LocalizationPL.mod
- KM_ScriptsEN.mod - rename to KM_ScriptsPL.mod
- Textures.vdf
- Textures_Addon.vdf

Just to be sure, I've also copied the Textures_Addon_Menu_English.vdf and Textures_multilingual_Jowood.vdf, not sure if these change anything.

Keep in mind this is my quick attempt at getting the voiceovers into the game and may break something down the line.

Looks like you actually only need to copy the Polish version's six "KM_Speech[1-6]PL.mod" files into the Data folder of the version with the English subtitles, and (optionally) rename them to "KM_Speech[1-6]EN.mod", as described in one of the reviews on the Archolos store page.

Works like a charm so far, but I'm not sure if this quick and dirty solution may be responsible for the text boxes staying on screen for longer than needed, there's often a noticeable gap between the polish voice over line having concluded and the corresponding text box closing and progressing to the next text box and voice over line.
Or is this delay present in the Polish-localised version (Polish voice over + Polish subtitles) as well?

On steam, the polish voice pack is available as separate download for the english (voice-less) version. So, no copying/renaming fuss.
Why not here on gog?!

You can download full version of The Chronicles of Myrtana: Archolos from moddb:

https://www.moddb.com/mods/the-chronicles-of-myrtana/downloads

It provides all 3 options to run mod, which can be selected in GothicStarter:

- Polish text and speech
- English text and Polish speech
- English text with no voice-over

Just downloaded from moddb, the lates vesrsion at least is not complete. Does not even come with an executable file...

Modifications for Gothic 1 and 2 do not have any executable files. Install them on top of the original games and select, which mod to play in GothicStarter.