Jon, I believe you have it right on the nose. Here is an objective analysis. A website I found has tracked the won-loss records and percentage for each D1 team since 1945 or the last 69 years. The average winning percentage of your A division is .568 and for the B division is .556 rounded to the hundreds or a difference of .012. OSU and Michigan are numbers 1 and 3 respectively in highest per cent win total. PSU and Nebraska are 2 and 4 respectively. Each division has four teams with overall winning records during that 65 year span: Michigan State(.574) Purdue(.510) in division A versus Wisconsin(.526) Iowa(.514) in division B. Among teams with losing records Minnesota comes the closest to a winning record at .474 followed by Illinois at .453. Indiana and Northwestern are at .381 and .367 respectively.
For football this arrangement is hard to argue with. I do not know how the Penn State fans would like it because of geography and you alluded to that. But if it is any consolation they would only have to make two or three trips west yearly until further expansion occurs and that could be eliminated. They would still play at least three other games in the eastern time zone.
Really? You are going to determine the divisions are equal based on records since 1945?