Yes, in the original conception, the Ian and Barbara characters (although the names came later) were supposed to be the hero and her0ine, while the Doctor was the eccentric supporting character. You can still see something of that throughout the first series.
I like the way Ian developed into a kind of action hero by necessity - he was a teacher, after all, but he found the reserves to do extraordinary things.
Edit - would you believe it wouldn't let me type her0ine properly?