When you write for a show that's not yours, your job is to hear the voices of the characters and write as best you can for those voices.
I think you can't go into any story-breaking process thinking, 'What if they come off as unlikeable?' You just gotta break the story because if you know who your character is, the story will tell you. The story will dictate and say, "This feels off-kilter for this particular person."
The way television works is that directors come in and out, and they're not there all the time, following every character through every scene. They're vagabonds who go from one show to another.