One can come up with theories, but I'm not sure there is a clear difference in outcomes between more hierarchical or more horizontal management styles, at least large enough to overcome all the other ways companies differ as an explanatory factor. To take two neighboring countries with many similarities but very different management styles, Finland typically uses a hierarchical management style, while Sweden has a very consensus-oriented, horizontal style. That produces somewhat of a "natural experiment" (though imperfect, like natural experiments usually are) where if one management style was radically better than the other, we ought to see big differences in outcomes between Finnish and Swedish companies. For example if your hypothesis is correct, Finnish companies should be much more successful than Swedish companies. But there doesn't really seem to be a big effect there.
You have a point, although it is more likely that the success of a hierarchical management style is more closely related to the effectiveness of the person in charge. Given that the one in charge isn't being undermined by next-in-command. Note: followers.
In my hypothesis I was already assuming a somewhat perfect leader and followers, which is impractical at best and unrealistic.
I do think it's time that people start valuing the individual more than the team. In my experience a team is usually less effective then the sum of its parts.
