[fqued]

One only has to look at Alcibiades to see this, the greatest traitor and most despised man in Greece

Alcibiades was first general for Athens, then general for Sparta, again general for Athens and finally admiral for the Persians. Maybe he was what you say ( can't speak to that), but he was also greatly respected for his abilities as a general--a Strategos. There is something great (whatever his vices) about a man who can accomplish what Alcibiades accomplished.

[Cicero]

Alcibiades was a great man gone wrong. He had tremendous abilities and the best training that Greece in the Age of Pericles could offer, but he went wrong.

I believe that is the significance of the role he plays in Plato's "Symposium."

Odysseus was a great man pure and simple. Achilles had one kind of arete in The Iliad, and Odysseus displays a different kind of arete in The Odyssey. It's clear throughout the poem that all the best Greeks admire him, from kings to swineherds.