Different manufacturers have different recommendations as to the orientation of off axis tweeters.You would have to read the spec sheet on each speaker to find out the reasoning.
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When you try switching the speakers side to side to see which you prefer (if either at all) listen for 2 things. 1) Clarity from reducing side wall reflections a tad (when tweeter is on the outside) and, 2)Soundstaging which should be slightly wider when the tweeter is on the outside and more focused when on the inside.
The key words are 'slightly' and a 'tad'. Many, if not most, folks wouldn't detect the difference for a lot of good reasons.