My completely uneducated opinion is to play as the companion you like the least in terms of personality, since you can then effectively change their personality.
If you really like Lohse as a character, take her as a companion so she acts 'correctly' to her character.
Playing as a companion, in my opinion, seems more like choosing an origin story in Dragon Age - you have that background, but you can still play completely how you want... and you're probably not going to play 1:1 with that character's personality.
If they're a companion, they'll be true to their personality.
Think I'm going to play Sebille because I hear she's an annoying edgy cunt if you have her in your party.