So if I were to rewrite the Wonder Woman film, here's what I'd do.
First of all, forget Zeus. The main goddess is Aphrodite. Love is the enemy of war. There's an elegance there.
When Diana wants to go back to man's world, her mother agrees...but only if Hippolyta herself can come along. Hippolyta's love (one of the black Amazons we catch only glimpses of—let's name her Sappho. Why not? Marston would approve) goes along too. Hippolyta and Sappho go in a separate boat, so we can still have the Steve/Diana boat flirting scene, since that's pretty much the best part of the current film.
When they arrive in London, Steve tries to organize things. But Diana and the Amazons quickly ditch him for Etta, who is obviously more competent, and also a British spy (keeping tabs on Steve.) She is won over to the Amazons mission, and sneaks them off to the front, leaving Steve behind (he gets to answer phones for the rest of the movie.)
In France the Amazons fight their way across the front (Hippolyta insists on no killing.) Diana, not Steve, gets into the ball and confronts Dr. Poison; sparks fly, and Poison reconsiders her evilness. While Diana goes to fight Ares, she leads Hippolyta, Sappho, and Etta to the poison plane. Hippolyta (not Steve, who is back answering phones) pilots the plane to explode. Diana and Dr. Poison defeat Ares. They grieve for Hippolyta, and Sappho returns to take Hippolyta's place as Queen of the Amazons (though she promises to keep in touch); Dr. Poison goes with her for reeducation. Steve declares his love to Etta, but she has important spy things to do. Diana mourns her mother and stays on mans' world to preserve the world her mom saved.
Or, you know, something along those lines. There should be giant kangaroos too, of course.