When I was in the Air Force, I was REALLY good at what I did. I knew more than my superiors' superiors and was sought out by anyone seeking knowledge. I could do the work of two of my peers and still put out a better product. But I kept being passed up for positions of authority for my peers, who were clearly not on my level as far as production goes. Finally, I got fed up and talked to my weapons officer, who was a Capt (I was an E-3 at the time).
He told me, "yes, I realize that you are considerably more capable than A1C whoever, everyone knows that. But you aren't a leader." I responded with, "that's not true at all, I lead by example. I'm just not in other people's faces or making a big deal out of everything" To which he responded, "No, that makes you inspiring to work with. Everybody sees your work ethic and ability, and it inspires them to match you, which does indeed make for much better work, but that's not all a leader does. A leader must correct things when they are wrong, help when people need it, take control and adjust the situation when it needs to be adjusted and praise when deserved. An inspirational worker makes a better product. A leader makes a better team."
We went on and he told me (paraphrasing) that most teams need both. A superstar and a leader. Somebody can be both (Tom Brady and Peyton Manning are). By this definition, I can't label Romo a leader, though I think he's an inspiration to the Cowboys.