Sure it will change over time, but let's look at ISU's schedule:
UNI, Iowa, Toledo
Kansas, Texas Tech
Certainly not a gauntlet, and comparable to Iowas: ISU, Ill. St., North Texas and Pitt, Wisconsin. Both have an upper FCS (whoopee) a Mac, rival, two P5 schools. I'd say Iowa has the edge with Wisconsin.
But then ISU hits TCU and Baylor. Going off of last year, those are two top 10s, whereas Iowa hits Illinois and Northwestern.
Big 12s remainder, imo, is completely up in the air. They could be mediocre-to-bad again (Texas, Ok St, W Virg), or good (Ok., K St.) or they could far surpass expectations (see Ok/Texas).
Iowa's is basically a dud, unless you are a midwestern football fan. Unless things vastly outperform last year, it is obvious that ISU's schedule is much "harder".
But, it is tied inextricably to TCU and Baylor. If TCU drops back to 7-win territory, and Baylor stumbles a few times, it drastically reduces their SOS. Obviously.