There was a time, after Doc Strange left, when. IMHO, the team became relatively weak (as much as any team counting the Hulk among its ranks can be called weak). They were Nighthawk, Hellcat, a weaker Val (when she was inhabiting Barbara Norris and not in her fully asgardian body), and the Hulk. The Zodiac saga, around #50, is one of my favorite Defenders sagas, however, I always found it'd have been more exciting if it had been done with a larger and more powerful line-up.
Peace