Well, maybe. It's been a long time since I've seen the surviving Vicki stories. But last year or so, I rented the DVD collections of the surviving episodes and fragments from incomplete stories, and Polly did come off pretty badly, much weaker and screamier than I remembered her.
And even so, the point is that Barbara was rather different from what we came to know as the typical female companion -- more mature, more of an authority figure. As they touched on in the opening documentary, the original format of the series was that Ian and Barbara were the leads -- the science and history teachers who would headline what was supposed to be an educational show -- with Susan as their pupil and the audience surrogate, and the Doctor as a mysterious, ethically questionable figure who was the catalyst for their adventures and often got them into trouble.