I don't have any personal experience with the upper levels of a large company, but maybe the mechanisms at the top are similar but the scale of the organization

I don't have any personal experience with the upper levels of a large company, but maybe the mechanisms at the top are similar but the scale of the organization is increased enough to result in a much higher ceiling for advancement? For example I'm wondering how much "know a guy" is required for being on the board of one of the big four banks.