Originally Posted by
Ryllharu
That quote is absolutely not true. It's certainly easier to get sneak attacks when you are solo, but as long as they have never spotted you, it's a backstab. You're hidden until they've seen you, not anyone allied with you. Shadow Warrior doesn't set you to [Hidden], they simply lose you for a second, making it easier to hide. Same as if you ran around a corner. It takes the "white" out of the eye, but it is still a discovered state.
I've had Lydia, Aela, Farkas, or Uthgerd the Unbroken be engaged in combat and I've performed a throat-slice execution while the enemy was blocking. More than once.