Even on my 10-years old desktop Cossacks games run too fast.

Cossacks 1 do have a Game Speed option in Options menu (F12). Cossacks 2 seem to have not such an option. So is there any way to change game speed in C2?

Answering my own question:

To change the game speed you must edit EngineSettings.xml file in the main game folder. It seems to be bad-formatted and the regular Windows built-in XML editor returns an error so you have to use Notepad.

There's 3 speed settings, DefaultCampaign, DefaultSkirmish and another skirmish-related one (for multiplayer games perhaps?).

These values seems to be reversed, i.e. 100 means very slow (too slow), and 10 means very fast (too fast). I set it all to 85, and this seems ideal and natural, infantry walks, cavalry trots, everything is comfortable now.