Good read, interesting choice as there are a lot of such examples

Probably greatness is most powerful if there are enough powerful mediocrities to work against.

some interesting ideas but something feels off with the language used.

Of course mediocre and bad leaders make their mark on history. But Carlyle's Great Men theory is more about paradigm shifts that Great Men can will into existence, not just random noise they bring along. The problem with GM theory is that there is only a handful of examples to support it. Napoleon is one such example, and it was undoubtedly the inspiration why the theory was proposed in the first place. People were trying to come to terms with the fact that one leader can have such a dramatic impact on the entire world.

This entire article tries to make a point that it's not just "great men" or "structural forces" alone being responsible for the course of history, but then completely misses the point again by labeling someone in power as mediocre and arguing that that mediocrity caused much of the events of the 20th century.

This once again causes oversimplifies history to a few people and some nebulous "structural forces", and provides an attractive but wrong model of how history developed. In software terms we would call this a "leaky abstraction", and this particular abstraction leaks so much it's barely useful at all.

The world is much too complex to be understood by examining less than at least a few hundred million people. That this is beyond the capability of humans is not the world's problem.

You could fit in most senior directors, consultants and sales VPs into that bucket comfortably.