Great article that is direct about the need to influence with intent if you want to lead. We can go round in circles looking at leadership models and reflecting on what strategy to adopt. Without the power, ability and intent to influence it's very hard to lead anything.
We've spent over 20 years at Common Purpose, as a non-profit helping people lead change, and a few years ago we settled on a persons ability to lead beyond authority as the key thing. At it's heart it means understanding how to influence without reverting to your position of power.
The thing I would add though is that you can't influence effectively without resetting your radar. You have to see and understand what people and organisations very different to you, and your training, are thinking.
For more see http://www.commonpurpose.org/home/books/beyondauthority.aspx with a note from David Bell - Chair of the FT