The request was to build Chewbacca "at any time" and let's be honest, there was absolutely nothing epic about him in a New Hope...
A case could be made for nearly all the heroes, as of "A New Hope", being less than epic.
Even eternal fan-favorite Han gets by more on luck, charm and boasting than anything and Jedi knight and General of the Republic Obi-Wan Kenobi is low on mojo.
What made them great, at this stage, was "how they were played" rather than "what they could do".