Athena would almost be more like Batman. She's specifically a god of strategy (Ares is more the god of war), as well as a civic goddess (god of cities), goddess of crafts and goddess of wisdom, making her kind of the 'god of skills.' Total Bat-god.
Ares, on the other hand, master of all weapons. Less strategic, and more of a enthusiastic brawler.
Artemis, Green Arrow on steroids. A super-powered archer, something rarely seen the comics. Probably a bit stronger and faster than 'the average' god, since she's way more athletic than, say, Dionysus or Demeter or Hera. Also a superhumanly skilled tracker.
Hephaestus, blacksmith of the gods, god of fire and the forge, would be the 'Iron Man' of the Olympian League, or the Steel, with a big hammer and adamant armor of his own design.
Apollo, the sun god, archery, can see into the future, and can bring the light and heat of the sun to bear. I'd tie all of the powers to light, with his shining light allowing him to peer into the future, on occasion (as plot demands), and his archery being the vehicle to deliver light and heat beyond touch range (he normally can glow and radiate heat, but by holding an arrowhead, can infuse it with the power of the sun, causing it to explode with a flash of light, or even into a deadly fireball, on impact). Him and Artemis, by far the superior archer, despite not having fireball-arrows, would make the Olympian League somewhat unique in that it'd have *two* archers.
Hermes, super-speed, and also invisibility (unlike the Flash, he can't vibrate through objects, but can move faster than the eye can see!).
Demeter, plant control, like Poison Ivy.
Hestia, hearth and home, goddess of the home fires. Seems all domestic and kindly until she seals you in a stone box that erupts from the ground around you and then fills it with fire... She may also be the one, millenia ago, who made the 'rule' that vampires can't enter a home, so be nice to Hestia.