I put up a this poll: https://riordan.fandom.com/f/p/4400000000003511048
And the results say that Poseidon is better than Ares, so instead of explaining what is bad about Poseidon (*cough* what he did to Medusa *cough*), I will explain why Ares is good.
First, everyone is like 'oh he killed so many people through wars' that is wrong because no one blames Zeus when someone gets electrocuted or Poseidon when someone drowns. We should be blaming the person that killed the other, also you don't blame Athena for someone dying in a war.
Second, he might have broken his own brothers heart be having an affair with his wife but... Okay I can't make that sound good.
Third, the main thing is the wars so what else did he do that was 'so wrong'
Ranking of the Gods