In my opinion the Greeks didn't think of Athena as a goddess who inspired war as Ares did. She was, to oversimplify the matter considerably, the incarnation of *techne,* the human ability to invent and improvise in order to overcome obstacles. That's perhaps why she takes such a fancy to the wily Odysseus.
I see why Marston chose Ares/Mars: he wanted to forge a link between the aggressive tendencies brought out in wartime and the anti-feminine repressiveness of patriarchal cultures. But I'd agree that war is not the only evil with which Diana might contend. Still, most comic book writers don't know much about real Greek myth, so we're maybe not missing much by their not giving us another portrait of Dionysus as a bibulous goat-man.
I'm assuming this is a place I can link to my review of the movie. I thought it had almost as many plot-holes as BVS, but it did cover them up better.