Sure, '3 yards and a cloud of dust' offenses, at least in the NFL at that time. The AFL was more of a passing league.
John Hadl led pro football with over 3400 yds passing in 1968 and Daryl Lamonica was not far behind which would put them by today's standards as slightly better than Goff's total last year. It doesn't change my 'eye test' though, Stafford is a better QB than Namath which was my original argument. Matthew has played a year longer and had more wins and the same number of SB victories. Namath is in the HoF due to hype (the AFL where he made his name was not as talented as the NFL at that time which made his SB win so monumental). Meanwhile Stafford is earning his way there....I hope.
I agree that it is a questionable comparison but ultimately it's the same game and most great HoF players from that era would likely be very good if not great in this one. And 1968 was the year I became a Rams fan!