@UltraM.
Believing that there is an overlap doesn't make it so, but neither does believing there's no possibility of an overlap.
...there certainly could be, and I would be curious to see further study on it ~ study by whom or how ? I have no idea, of course.

It makes little sense to me that folks with iqs 140+ are going to easily follow someone with iq 100; they might *think* they are working with someone who is 'nd', however it is highly unlikely they'd follow and feel confident about someone who was not at least 'bright' and then some. imo, based on my own comfort and confidence when working with managers, CIOs, etc. - I am much more inclined to do what someone says when what they request is 1. intelligently phrased and 2. logical.
I suppose this will vary with what folks are being led into...