What about the following criterion for correctness (which appears in Rabbi Kook, in Rabbi Kellner’s interpretation)?
A proposition is more exemplary, more proven, the more general it is. That is, a principle, line of thought, or method that explains more phenomena in a more logically continuous way—the more general it is, the more correct it is. The more numerous the phenomena that are explained systematically, the more justified the claim is than a claim that, according to its line of thought, explains fewer phenomena, and the certainty of its correctness increases.

That’s true, but when you get to actual implementation there are lots of reservations (how simple it is—Occam’s razor, how plausible it is, whether it fits experience, various a priori assumptions, etc.). Which is why this doesn’t amount to a sharp criterion.

Of course, this has nothing specifically to do with Rabbi Kook or Rabbi Kellner. These are very old ideas.

So what if we take this criterion and add two more criteria to help: correspondence to reality and predictive power? Are we in a better position now?

Definitely, except that now it’s no longer philosophy but science.

And is that critical? Meaning, isn’t the main thing simply that we have a good way to clarify things? And is it less important exactly which field we’re dealing with?

You asked where people acquire philosophical assumptions from. If you want to discuss something else, ask a different question.

Got it