ISU beat OSU. Why would they need them to lose again? What am I missing?
Three-way and four-way scenarios if ISU wins out (thanks to mred's generator):
ISU/OU/OSU/Texas: OSU gets first for complicated reasons. OU gets second for beating ISU and Texas.
ISU/OU/OSU: OSU gets first for beating KU when OU and ISU didn't. OU gets second for beating ISU.
ISU/OSU/Texas: OSU gets first for beating OU when the other two didn't. ISU gets second for beating Texas.
ISU/OU/Texas: OU gets first for beating ISU and Texas. ISU gets second for beating Texas.