In my view I believe that Ovid’s view of the Greek gods’ ethical performance was very simple: there was none.
If you are talking about the word ‘ethical’ in terms of pertaining to right and wrong conduct, Ovid’s gods were very unethical, ethically speaking, that is.
For example, a certain god might have a competition with a human, if the human beat the god, the losing god might turn the human into a spider or something else because the god was too prideful to have been beaten by a measly human. Another example is that when a rebellious human would gloat about how wonderful she was compared to a certain god that certain god would kill the gloater’s loved ones or hurt the human in some other way, leaving the human in deep sorrow and distress.
Then there is the example of the “good” and favored humans who were treated fairly and sometimes were even made into gods.
I suppose the gods might have been a bit ethical, but seriously, would you like to be under the domain of a god who punished you for winning a game? I know I would not. The whole situation just doesn’t seem too ethical to me.