FormerlyHemlock
Hero
And, it's not being directly mentally manipulated - no telepathy or magic nor even verbal communication is involved. It could be something as simple as a big, obvious attack that's easily avoided by stepping to that side. You could have stood there, but you'd've gotten pasted. Also, while we can think things through and weigh options, acting and reacting in HTH is presumably more a matter of instinct & training than deliberation.
And if I were the player, I'd want to know and decide that option myself. "Instead of abandoning the princess and moving 40' and also getting hit by the Maneuvering Attack arrow, I'm going to stay between her and the archer. I don't care if that means the arrow auto-crits me, it's totally worth it. Besides, Deflect Missiles reduces the damage I take by d10+12 anyway."
If you force me to abandon the princess and run away just because the rule says you can, I'm liable to be peeved.