New Brevoort Formspring

In your opinion, is Thor a "leading" avenger? i ask this because, despite him being the spine and the big hitter of the Team in most versions, he has rarely taken the Lead, despite his millenial experience in battle and his tactical ability. Does being in the Avengers limits his scope,usually cosmic/mystical when on his own, or is it a question of selfimposed restriction in the affairs of mortals, limiting himself at lending an hand to avoid messing with humankind's destiny?