I know this is cherry picking a bit but a quick look at the opponents Iowa has played en route to a 6-0 start:
Overall combined record 18-14
Overall combined record against opponents other than Iowa: 18-8
Take out North Texas and the overall record of the other 5 teams Iowa has beat: 18-3
Overall combined record 18-14
Overall combined record against opponents other than Iowa: 18-8
Take out North Texas and the overall record of the other 5 teams Iowa has beat: 18-3