They are really about tuning into your internal, spiritual warrior: that part of you that chooses right over wrong, good over evil. In the Bhagavad Gita, we read the conversation on a battlefield between Krishna and Arjuna, as two armies prepare to fight; but it is clear that the universal enemy is ignorance of the self.
'Kill therefore with the sword of wisdom the doubt born of ignorance that lies in thy heart. Be one in self-harmony, in yoga, and arise, great warrior, arise.'
That said, though, I maintain that if you practise a Warrior pose before a tricky conversation, you will have a better outcome!