Also, don't forget that the NFL was not nearly the passing league back then as it is now. Couple that with Fergy, who was very green and didn't throw many passes during the early/mid 70s, and I think it accentuates the talent those three guys had.
But I do think you're right, if we're considering the best starting two, I think I'd go with Butler-Lewis. If Chris Burkett didn't turn out to be such a head case, he and Reed were a promising duo.