The other characters, while having VERY different "tone" and "inflection," and VERY different personalities, don't seem to have dramatically different speech patterns when it comes down to mannerisms and the actual syntactic structure of their statements. The structure of dialogue across companions seems to be rather uniform, except for the odd line here and there.
Interesting. That’s not my impression though I can see why someone might have that view. Lae’zel of course, as a githyanki, is going to be most different but while the others are all from around the Sword Coast so are going to speak in broadly the same way (it would be odd if people with the same first language employed significantly different sentence constructions), I still find they very much have their own tone and mannerisms. Astarion is quite dramatic and sometimes even camp, both in his language and performance, and he has a sort of eloquence that makes sense in light of his history as a noble and magistrate. Gale is more of a nutty professor, amusing and eloquent like Astarion but in a different way, perhaps drier and a bit more sarcastic, and certainly degenerating into verbosity at times. Also like Astarion, his performance is quite physical with a lot of gesticulation, but in more the manner of a charismatic teacher than a performer. Shadowheart’s manner and language is more contained and conspiratorial, often seeking to build a rapport with the PC (befitting a manipulative Sharran) with bursts of defensiveness and sarcasm, especially when challenged. Wyll, as I’ve said elsewhere, I think is really poorly animated at the moment which makes him hard to judge given his weird jerky movements and peculiar facial expressions. But his speech pattern is the most distinctive, with the way he refers to himself (or “the Blade”) in the third person and employs hyperbole and almost bardic language to talk about our plans and exploits.
That said, I would agree that our companions do lack a certain amount of diversity just because four out of five are from the Sword Coast and the three male companions all seem to be from relatively privileged backgrounds, and perhaps this does manifest in the dialogue to some extent. We know we’re going to get Minsc and Jaheira from further afield, but hopefully we’ll also get other companions, camp followers and allies from different races and other locales who might speak in more distinctive ways and with different accents.
I do think, however, that the companions we have already have the potential to be as distinctive and memorable in their own ways as the DA:O companions, but I guess we’ll see how Larian polish and develop them in the full release and who they add to mix things up a bit.
Also a lot of the characters are perpetually horny in banter?
I do think the early banter about someone waiting for them at home comes across as weirdly high school-ish in practice, though in principle asking about someone’s family and who might be missing and worrying about them is a perfectly valid thing to ask about someone you’re trying to get to know. (In fact, it is a bit weird that no one, including Tav, asks early on about whether anyone is worried about friends or family who might also have been caught by the illithids.) And Wyll’s flirting with Lae’zel and then Shadowheart is a bit much, though apparently is included mostly for comedic effect. And Gale is at his worst when sleazing over Shadowheart, though again I’m not sure how exactly to read his interest. Is that the sort of stuff you’re thinking of?