Yes, both Iowa and ISU schedule was easier when they played 8 conference games. Going to 9 conference games when you are a bad program is tougher. Yet to think 6 wins is difficult is stupid. Beat the bad teams on your schedule and a couple average teams and you win 6 games.
So comparing Mac's record to anything recent is kind of apples and oranges. Also it's not the going to 9 conference games that is tougher it's not getting the chance to avoid good teams like when ISU used to dodge Oklahoma and Texas and Iowa dodges Ohio State almost every year