It's all unclear to me how his judging preferences are set up. When he's in action, he seems very much like an extroverted thinker. When he voices his opinions, i'm unsure whether they're syntheses of Ni-Te or largely Ti-governed. A good example would be his discussion with Keiko about the heart and the brain. Fi was very much absent during that conversation. But if we were to examine the Se-Ni thing going on with him a bit more...
Looking at a snapshot of his character from afar, though, he looks like either a mature ISTP, or a mellowed-down ENTJ. From a shallow perspective, his physique, accuracy with the gun (he did shoot that second grenade in mid-air after all) suggests that his preference for Se is not at all on the inferior spot. I reckon that if he were INTJ, it's more likely that we would see a slightly different Shogo from what's in the story. (I know the one in the movie is NOT xNTJ)
It would also make sense if we were to assume he's ENTJ. In the past game, his impulsive killer instincts coupled with his mental conditioning ("they are not my friends" x100) makes me think that he uses Se and Ni almost hand-in-hand in every decision he makes. This would be true for the ISTP also, and though the two types have a similarity, they are also very different from each other. It's almost like Shogo is the perfect hybrid of both.
Really undecided if Te-Fi or Ti-Fe. What's your verdict?