And what he had explained to you is that, while Oswego may have some nice big teams on their schedule, overall Norwich comes out ahead of Oswego in both OWP and OOWP... aka the components of SOS. In other words, in terms of raw number, Norwich
WINS the SOS comparison with Oswego. Im sure he'll correct me if I'm wrong, but I do believe he has repeatedly stated that he calculates the OWP and OOWP by adding the total number of wins/losses by all opponents (excluding the games played with the team in question) into one large W-L-T record and determining the % of that record.
I'm sure he didn't arbitrarily pick the margin of error. My guess is that the margin of error is a product of the low sample size (25 games isn't much, after all) and the inadequate crossover (i.e. not everybody plays everybody). Want a smaller margin of error? Play an 82 game schedule in which everybody plays everybody... oh wait... that's not DIII.