Iowa actually had a pretty good redzone defense, if you take a closer look at the numbers. They allowed 29 trips into the redzone. Opponents scored 24 times (83%). However, 10 of those scores were field goals (42% of all redzone scores allowed). For comparison, look at ISU's redzone defense (which finished #2): 48 trips, 32 scores. 27 of those scores were TD's (84% of all redzone scores allowed). I'll take a redzone defense that allows scores 83% of the time if they're forcing a lot of field goals over a redzone defense that allows scores just 67% of the time, but gives up a lot of TD's.
Now, back to Arnaud. I'm not sure if he really struggles with the short passes per se, but he has seemed reluctant to stay patient. He can move the offense if he stays patient, but too often he gets antsy and wants to make the BIG play. That's when he gets into trouble. I'm not sure if he's the right QB to beat Iowa. Up to this point, he's just not been patient enough.