If South Carolina was in the MWC, and Arkansas in the WAC, they would probably both be undefeated and in the top 5.
Both the WAC and MWC have two ranked teams each. The SEC has six ranked teams. That is half of the 12-team conference. The SEC Western Division has five ranked teams. Not only does the SEC have more ranked teams than any other conference, but the SEC Western Division has as many ranked teams as the entire Big 12, and more than any other conference.
Yet thos conferences keep getting their asses handed to them when they play a non BCS team in a bowl game.