"Centrist = Fe, Radical = Fi?" is indistinct.
Your thread title should thus read:
Centrist = Fe, Extremist = Fi
That's a better word pair.
Or - let's notch it up another:
Conformist = Fe, Extremist = Fi - that's much more provocative.
And for the record - I disagree with such generalizations. I don't see either tendency more predisposed to one preference or the other.
But words are just a veil here - if you want a hale and hearty discussion, it would be best if you provided definitions for what you see as each, make clearer what you want to get out of this thread.