While smaller in enrollment, the top tier of the WIVC is much better overall than the top tier of the BDC historically in the playoffs.
Camp Point Central
Calhoun
Brown County
Greenfield-Northwestern
Carrollton
Or
Johnston City
Fairfield
Flora
Sesser-Valier-Waltonville
Carmi-White County
Dont get me wrong, both leagues could afford to schedule non conference games and both leagues have teams that are not competitive. The south has trouble, outside of a few outliers, when it comes to the state finals. Is strength of schedule a factor? Yes, but its not the only reason the non closed conference teams have more success.
For 1A, its the NUIC's world and the others are just living in it.
The BDC has won two state titles in football. Zeigler-Royalton (now a coop with Christopher) in 82 and Carterville (now in the Southern Illinois River to River) in 96.
The WIVC has been a bit more successful with six titles. Triopia in 75, Routt Catholic in 84, Calhoun in 93 & 94, Triopia in 08, and Camp Point Central in 22.
Whereas the NUIC has 27 state titles in football. Plus five more I8FA championships too.
Just as an aside... the Okaw should have never disbanded. I understand feelings got hurt, but, for example, look at where Argenta Oreana is now. Last year of the Okaw, 2013, they beat DST and hung around with Monticello.
You had years where there were multiple representatives in 1a, 2a, 3a state finals.
2009 - 1a Tuscola, 2a MF, 3a Tolono
2010 - 1a Tuscola, 2a MF
2012 1a - MF, 3a - Tolono
The CIC wasn't half of what the Okaw was, and the same hurt feelings eventually showed back up. Part of why the NUIC is enviable. Yes, it's great competition, but it's great competition because the teams up there rise to meet the challenge of Lena/Forreston/Stockton etc. They don't say "well Lena has won X titles, we need to kick them from the conference"