Let's consider the possibility that labeling makes irrational disagreement easier. If you and I disagree about something, maybe that's because at most one of us is right. But once we learn that you're a Green and I'm a Blue, the discussion is over--we're just different stripes, that's all.
That said, if we're going for a term that has minimum transition costs associated with switching to it, why not technical rationality or quantitative rationality?They're just different enough from plain ol' rationality that they might prevent confusion.
You see, I've seen the word "rationalism" used to mean all five of these things at different times:
Edited to reinstate that proposed solution, since this discussion is presumably finished.