So the success of this show is riding on the Atom? Good luck with that.
Err, no, it's riding on Brandon Routh. As well as Victor Garber, Caity Lotz, Wentworth Miller, and Dominic Purcell. Actors are what make TV shows work. The characters are just the material they work with. Felicity Smoak was a minor character in the comics, and her Arrow version was initially just an occasional supporting player who was mainly just a plot device, but Emily Bett Rickards's charm made her a breakout character and the heart of the growing CW superhero universe. (Or maybe the muse. Every guy who has a crush on her ends up becoming a superhero.)
See also Agent Coulson, a character who didn't exist in the comics, but who became an indispensable part of the Marvel Cinematic Universe because of Clark Gregg's charisma.