Those are all good questions. Similar to these...
How good is North Posey or Southridge, really? I saw HH at NP and NP looks a lot like North to me, with less size on the lines and less speed at the skill positions. Most of Southridge's wins are against the PAC equivalent of Central, Harrison and Boose, right? Boonville is not good. Mt. Vernon is always mediocre. Gibson Southern is in the same boat as Reitz, lost some key players to injuries.
In reality, the PAC and SIAC are usually pretty similar. One or two very good teams, a handful of decent teams, and some perennially bad programs that struggle to compete.
My comment about Sagarin wasn't that the SIAC is better than the PAC, it was simply that I don't believe the SIAC numbers are accurate based on what I understand the methodology to be.