I forgot until this post that there's other barbarian subclasses. The game funneled Karlach into Wildheart, might go respec her into berserker. Our party is already really good at focusing down big single targets so long as my wife and Astarion stay up, we even managed to take down the bulette in one round.
Even after I respec'ed her, it skipped the menu to choose a subclass, defaulted to Wildheart, and had me choose an animal. I had to go back and switch from Wildheart to Berserkr. The option was always there, it just skipped some steps and I didn't notice.