The ideal rationalist is the one who only ends up arguing true beliefs, and who, when presented with anything else, throws up their hands and says "How am I supposed to make that sound plausible?"

I reply: I'm paying you a lot of money. You'll find a way.

When I say or hear "rationality", I think of the tool, not of the noble "ideal rationalist" whose only pursuit is truth, not money or other personal interest.

That which can be used to argue for any side is not distinguishing evidence, whether "that" is a strategy, a person, an outlook on life, whatever.

Rationality is winning. I'm hiring a master rationalist to make me win my court case. What's not to like?

A rational debate and agreeing on objective truth may be what the arbitrage system wants. But what the individual disputant wants, in the end, in an important enough court case, is to win. If I have to game the system to win, I will. (It doesn't help when we create legal entities like corporations, which are liable to get into many more trials and also to treat many more trials as all-out war where winning is paramount.)