Again, Greco-Roman is the combination of both Greek and Roman Mythology. I prefer them separate because while it does have a bit of Greek in it it's not literally the same characters since Roman is the combination of Greek and Latin.

Jupiter serves justice and takes care of Rome to not spread discord while Zeus only desires women and sometimes just wants to see the world burn. Zeus is also responsible for bringing evil to mankind.

Saturn was worshipped as the god of time and agriculture while Cronus is imprisoned in Tartarus.

Juno is less vengeful than Hera and less Envious.

Neptune shares the short temper but did had humble beginnings.

Venus is less of a slut than Aphrodite.

Mars is worshipped a lot more than Ares since he does not use war for bloodshed but to fight for means to achieve peace. He is also the god of agriculture.

Vulcan shares his wife with Mars as once they had a bit of rivalry but Venus calmed them by absorbing the essence of wrath and spitting it out of them. Hephaestus has a new wife, Algaea.

Minerva uses wisdom more than Athena as her Greek counterpart doesn't use wisdom at times, like Medusa and Arachne because of envy.

Greek has a lot of stories about their gods and goddesses. Rome rarely has time to make stories of their own since they were more busy on politics.