I look forward to H1's response to your follow-up question, Fritz.
Here's a couple of my thoughts from what I've observed in 3+ years and my recall from the trainings.
Use of shadow power does not imply malevolent intent WHEN UNCONSCIOUS. When someone circumvents the rules, or governance that was created through the rules, they may be doing so out of ignorance. Relying on previously learned behaviors or habits in those instances may simply require some wake-up calls and re-education.
But when there is intentional deviation from the rules of the game - even if someone does not mean to cause harm to persons, teams, or the organization - then I'd argue that it is, in fact, destructive.
This type of deviation can come from different angles and with energies. A former manager/CEO or simply someone who is used to bossing others may bring a dictatorial style that asserts authorities they do not have. Others may be so inured to a hierarchy of power that they seek permission/approval or 'buy-in' constantly - especially from those like that CEO type whose influences far exceeds their role definitions.