I agree with them being opposed to Tav. I don't mind it either. Actually I kind of like it. I love when they rub against Tav, like Shadowheart and Lea'zel in Act 1. Astarion even though he is my favorite don't always agree with my Tav. Something about Karlach though just don't work for me. She was just a constant nay-sayer at the back of the group.
In my experience Karlach was very much right in front and in my face whenever she disagreed, however the only real major disagreement I've seen with her is making a deal with Raphael as she is usually more on the same page as my characters (we like to swear and kick things).
Lae'zels and Jaheiras introductions are my favourites actually, because they are not friendly, but extremely practical. Lae'zel would never had even talked to us in a different situation, but she knows, she needs help and is honest enough to take it. And Jaheira was never someone beating around bushes, so that fits.
What I do like about both Lae'zel and Karlach is, that they are totally honest from the beginning. It's refreshing, since that is not do often the case with videogame companions and the others are not so forthcoming. Well the non origins are, but for them, there is no reason to lie. I'd probably not want to tell complete strangers, that I worship one of the most evil goddesses, being a vampire, having to consume magic or turn into an atomic bomb or being a fiendlock. Minthara and Halsin are already known to the group when we get them, though I did thought, we would find out, that Haldin is a werebear tbh, since he doesn't seem to have his bearshape under control, when even a level 2 druid can do that, and they scratched the werewolf origin.
I am always amused at how confident Lae'zel is in her superiority. Like she is literally caught in a cage about to get killed off by two tiefling commoners and yet she still acts like she is irreplacable. But I also have to hand it to her, that she backs that up. The standard solution to every challenging encounter is to simply apply Lae'zel.
