Cosmic Ret-Cons and nonsensical renaming.

The way the Romans adapted and adopted Greek myths as their own reminds me of what happened when Disney bought Star Wars. They renamed the characters, reorganized the entire history of the universe, and yet when everything's said and done, most of the same events happen, most of the characters are the same, but with slightly different names, and the order of events is slightly different. In fact, the Roman attitude toward Greek myths is also very similar to what happens with a lot of comic-book adaptations to any other medium. It's more akin to having read the original comics, then watching an animated adaptation. In fact, all of the the Greco-Roman mythological variations strike me as very similar to what happens when one story is adapted multiple times over centuries or decades, much like many comic book heroes, or indeed, other literary characters such as Robin Hood.