Hi Emorrisiv. I'm fortunate (or cursed, depending on your viewpoint!) in that my preamp affords remote control of absolute phase, AKA polarity, from the listening position. I try to determine the best polarity setting for any recording before listening (other than sometimes casual or background listening), and have amassed experience in doing this with thousands of recordings over several years.
The truth I've found is that many, if not most recordings are either only mildly sensitive to polarity at best; or apparently insensitive enough that I can never be sure which the preferred or "correct" setting actually is; or display one preferred setting for one solo instrument or voice but the other setting for another soloist; or confusingly display opposite preferences for soloists vs. backgrounds; and/or vary in these regards and thus the preferred setting from cut to cut on an album. And I often find that it's quite possible to convince myself that one or the other setting is "correct", only to change my mind upon subsequent relistening (additionally, this can change as I vary my listening distance within the room, or even the volume setting).
On the other hand, many other recordings do seem to show a polarity preference that's constant and not difficult to determine. In the final tally, I'd guesstimate that I do determine a setting which I prefer on balance for around 85% of recordings (the other 15% being pick'em). The funny thing is, try as I have, I can't really say that these recordings possess any likely characteristics in common, such as being "minimally miked" or "naturally recorded". Sometimes "purist" or live recordings you'd think would be a slam dunk in theory are impossible to determine the "correct" polarity with, while some heavily multitracked studio creations are quick and easy to determine.
However -- as you'd expect given the disregard to polarity throughout the miking, recording, mastering, and production processes for most recordings, and the fact that most playback loudspeakers aren't so-called "minimum phase" designs but instead use high-order crossovers that rotate phase and multiple drivers often wired in opposing polarities -- in the end, the breakdown between "straight" and "inverse" settings in my experience approaches a 50/50 split with those recordings for which a preference can be determined, with maybe just a 10%-15% tilt toward the nominally "correct" setting when using 1st-order or single-driver, minimum-phase loudspeakers.
The upshot of which is, I'd be leery of declaring one or the other polarity setting best for any arbitrary group of recordings based on some incidental characteristic such as country of origin. Especially if you're having to reverse polarity by reversing speaker leads, since that doesn't allow for rapid, multiple A/B comparisons from the listening position -- it's just too easy to confuse or convince onesself that way. But having said all that, I do commend you on bothering to experiment with polarity, and can only say "go for it and enjoy it!" if you've found any rules you can live happily by.
