I'm not an expert, but Greeks looked down on pure aggression and power without thought or strategy. At least the aristocratic Greeks, though presumably their standards also became the standards of the lower classes.
Achilles lets his emotions carry him every which way, whereas Odysseus does not. Both are powerful men, but one is also very intelligent and in the Odyssey he is someone to admire, whereas Achilles in the Iliad is not somebody to admire. Heracles also succeeded against many beasts despite being half human, because he was more intelligent than them while also being very strong. Beasts (generally) just have raw power in Greek myth, at least the beasts/monsters that are fought. Whereas gods, goddesses, higher 'monsters', and the higher echelons of humans have both power and wisdom in varying degrees. Uranus had his nuts cut off because Cronus was more intelligent and outsmarted him with the help of Gaia. Cronus then feared his own son would would steal his role, so 'stored' them within himself rather than store them in Rhea like Uranus did with Gaia. Zeus then usurped Cronus with the help of Rhea and the monster-children of Gaia (and others? I forget)
Zeus was the wisest of them all, and he feared that a son would be more wise than him, but instead Athena was born who probably is much more wise than him, but is a woman.
He is also more sociable and charismatic, and thus has some powerful allies.
Speaking of Athena, Athena is held in much better regard than Ares despite both being war gods, because Athena is wise too.
You can even look at Greece itself to see this belief: they couldn't keep up with population growth due to the limited viable agricultural space, so Greek nations colonized and traded. They worked hard through agriculture, but also smart through trade and colonization.
In short, Homer is providing (and very likely reflecting) moral values through them being personified.
Hope this helped. I apologize for my ignorance of the Iliad and Odyssey, as well as various other mythologies. I haven't read any in full in a very long time, and am just now sparking my memory.