I agree OP, our current ragtag of companions are...random. of all of them, Lae zel is the most macho. But of our 3 gentlemen. Gale is a edgy wizard teen about suicide, astarion is a pretty boy Casanova, and wyll is a theater drama nerd.
If Halsin could be a companion, now that is a chad to bring about to the fight and adventure with.
These are the types of companions you get when you try to make special companions with special problems. It’s a cover for bad writing. It’s harder to develop a plain character that’s interesting than a character with a special plot hook.
Halsin is a pretty plain druid. He loves nature and is concerned about a dark presence. He’s not edgy. He’s not insecure. He’s not weak. And he’s also interesting without the drama and someone I’d like to have in my party.
This sounds like a cross between a Personal Ad, and a song: "And he likes Pina Coladas, taking walks in the rain..."
Aside from that, I do agree that the cast of characters could use some more variety in personality (and of course race and class) - perhaps some maturity, some level of positivity, some more in the good to neutral, mix. While they no longer use the actual good/neutral/evil/lawful/chaotic labels, the current cast does seem to tend more to the lawful evil, chaotic neutral spectrum - I couldn't imagine having a close friendship with any of them thus far. Complex motivations are not a bad thing in general, but they should not consistently overpower other aspects of a personality.
Minsc got a bit nutso and dark in wanting to rescue Dynaheir, but it didn't stop him from being upbeat, outgoing, friendly and a bit bonkers - I used to partner him with the sword Lilacor, just to hear the two of the babble back and forth, with a rodent sidekick. Edwin's personality took on new dimensions once he was Edwina. If BG1 and 2 could manage such different personalities and character growth even on the basic level they pulled off, I hope Larian can manage similar range - though much of it might not appear until we get closer to full release. DoS2 certainly manages a cast that wasn't, on the whole, unlikable.