How Achilles, Agmemnon and Patroclus demonstrated leadership?

I'm sorry, I just read through the first nineteen pages of the novel, and I do not see evidence of leadership traits in the pages cited. We learn the backstory of Achilles and Patroclus; we see Agamemnon's claim on Briseis (he is described as taking her from Achilles in "his lordly way), and Achilles refusal.

The only character that truly displays leadership is Patroclus, who takes Achilles place when Achilles refuses to fight. He dresses in Achilles armor and leads his men. Sadly, even this might be considered a rash move, as Patroclus achieves nothing more than the loss of his life.