You're joking, right? Sullivan was easily one of the worst, if not the worst, QB's in ASU history. I don't feel like scrolling threw the record books pre-1990 but his season last year has to be the worst of all time.
110 QB rating ranked him 107th out of 115 D1 QB's. This isn't the NFL where a 110 QB rating is good... A 110 is AWFUL in college.
6.2 YPA ranked him 105th out of 115 D1 QB's.
53% completion percentage ranked him 104th out of 115 D1 QB's.
1,900 passing yards ranked him 87th out of 115 (granted, he didn't play 2 games).
Threw for more than 250 yds twice.
About the only bright spot was he threw for more TD's than INT's. Doesn't say much when you only throw 10 TD's compared to 9 INT's.
As you said, there was more to the problem than just Sullivan but he is easily one of the worst ASU QB's ever.
Much of that was a function of the offense and the inability of receivers to get open. In addition, he was TOLD to throw the ball away after going through his reads. There was no coming back to a developing route because Erickson didn't want to take a sack. There were big red X's on some routes and were only used to clear out space underneath. ASU didn't not take the field in any game with a full playbook or the full confidence in the passing game because of it.