After further review, here's how ORU's current "magic number of 2" plays out:
If ORU sweeps Omaha, they're in no matter what NDSU does.
If ORU wins 2-of-3 at Omaha, they're in no matter what NDSU does.
If ORU loses 2-of-3 at Omaha, they are STILL in unless NDSU sweeps SDSU.
If ORU is swept by Omaha, they need NDSU to lose at least 2-of-3 to SDSU for ORU to get in.
Of course, this assumes none of the six games in Omaha and Brookings get rained out...