I believe it would be interesting to see a Ne and Ni fight it out. I believe that would be that only true way of knowing what will happen, because if the Ne sees the path and the Ni sees the answer. Then the Ne could easily change part of the path to get to a different answer, and the Ni would see that answer and then back and forth back and forth. That would be one hell of a battle.
To answer your other question. No I don't believe it's the functions you choose to show. I believe you are born with dominate functions, sometimes borderline dominate, but you can strengthen all your functions.