I think the leadership is less important than the culture of the country. i.e. countries with a culture that make it possible for women to fill these top posts are going to do better.
That is the trouble with these kinds of studies. It is impossible to know the direction of the causal relationship even if one actually exists.
i.e. a researcher with a predetermined view on what answer they wanted could sift through all of the economic data available and look for those statistics that show the desired correlation while ignoring those that don't. They would then write rationalizations for why the metrics chosen are valid. That is why these kinds of studies should never be taken seriously especially if they seem to confirm what you would like to believe (and yes I take my own advice).