By the way, I found a mistake in the skill wheel: the "Sudden Attack" skill is granted after finding the path, not after scouting.

Really? I'll have to check. I've never leveled up this skill, so I don't know for sure.

It's been known for a long time that there are errors in the skill wheel located in the game's directory.
And the updated and corrected version, Skillwheel_rus.3.0.1a.exe, has been released for a long time. Besides the error in the Warlock's skills ("Sudden Attack"), the Demon Lord's skill ("Master of Gates") was also fixed, and maybe some others (I don't remember anymore).

P.S. I just checked. The file archive on heroesworld seems to have an older version of the skill wheel (version 3.0). The administration should update the file (the latest version is available on Google Drive, for example).