Here are a few examples:
Ra's willingness to adapt the offensive strategy of The League of Shadows to match the unique fissure points in Gotham's culture - her profound susceptibility to criminal influence; blurred/polluted lines in enforcement of law/ethical mores; sophisticated comprehension of the relationship between economic vulnerability and emotional weakness ("Create enough hunger and everyone becomes a criminal...") speaks clearly to an individual able to accurately convert broad sociocultural pattern into a singular plan of action. As you know, powerful Ni is the ability to concisely forecast data cultivated from extraneous "white noise".
I see your connection to Ra's dedication to tradition. Tradition, I suspect, is of secondary importance to his ultimate goal of eradicating unsavory elements within the human condition that prevent us from "confronting truth" (See: The Will to Act segment)
He is fundamentally an abstract thinker. Tradition is simply his instrument of choice in furthering his essential desire to reduce psychological dependence on "untruth".
He is willpower, given human form. To this end, Wayne's intense focus is offered perhaps as a consequence of Ra's.
Thoughts?
While watching the movie I got the impression that Ra was "the shadow" of Bruce Wayne. Him and Batman were similar people who worked for different sides. They were both guardian angels, in a sense, who only appeared when they were needed.
Ra talked about how The League of Shadows waits patiently until they are needed. How they are the enforcers of mores and justice. When the scale is tipped, they appear to set it right. Batman was exact same thing, only he appeared to protect, not to destroy, like Ra.
When I try to type a person (or a character), I try to go for the essence of the personality. What is the driving force of that person? Not so much what he says, because people may speak in a different way depending on how they are raised or what their profession is.
Ra's driving force appeared to be the sense of duty to set something right when it went wrong. An obligation to the human civilization. A surgeon who must remove the tumor, even if it brings the patient pain. He was entrusted with this obligation by being the head of The League of Shadows. To me that's spells SJ.
Ra had that philosophic streak in him that you mention, that's true, but that doesn't make him an N. Every monk is a philosopher to a degree, and that's what he was: a warrior monk. You also have to take into consideration that the guy is centuries old, so he had extensive wisdom that comes with it.
The League of Shadows did adopt different techniques over time to do their work: fire in Rome, disease in London, economy in Gotham. And its true that SJs tend to be more rigid when it comes to adaptability than NTs. But if their job specifically calls for adaptability, SJs can learn that skill and wield it competently. For example, it could have been in the order's training manual that one should never repeat the same tactic to destroy a city because it lowers the possibility of success (no element of surprise), due to the fact that societies learn from great disasters and protect themselves accordingly.
