The Duality of Friendship

According to Plutarch, and perhaps Aristotle's, "another self", the duality of Friendship is two-by-two. From Moral Essays, Plutarch pairs Theseus with Pirithous in a hell bound relationship worthy of legend. Achilles and Patroclus are the center of a romantic controversy. A controversy of interpretation between Plato's and Xenophon's Symposium. Socrates advocates a romantic relationship between Patroclus and Achilles in one version. Which do you think is Platonic? Later, Alexander the Great in his life long Friendship with  Hephaestion raise similar eyebrows. I am indifferent to these details. Friends are friends, lovers are lovers, and so what if the two shall meet.