Well, at least Sensia 100 is completely different from Provia 100F. Just shoot them and you'll notice that Sensia 100 has greater latitude, particularly in highlights, and neutral, not so vivid colors but not dull either. This is just like Astia. Provia looks different.

Emulsion codes also suggest Sensia being a sibling to Astia; Astia is RAP and Sensia RA. On the other hand, Provia is RPP and Velvia RVP. The third P is probably for "professional" .