who is at the helm?

Considering X is heading big business group in India and group has multiple companies in automobile, chemicals, steel, IT and finance sector. However being owner of bellwether he has to delegate power to many people who are almost as powerful as the owner, although in the ambit of individual companies which they head. In doing so i.e. delegating power, isn't parent owner risking his reputation as these so called heads of individual companies may go wrong and impact group's reputation? Or it is imperative that these companies should be treated as individual firms with their own future and reputation being in the hands of people who are at the helm of these companies?