I'd venture to guess that most offenses don't put up good numbers vs really good defenses. Or else, they wouldn't be really good defenses.
We put up 1.05 points per possession vs St. Peters. Which doesn't sound like much. St Peters has a highly rated defense despite being a 15 seed. When you factor that the predicted score on Kenpom given where the two teams were ranked was 74-59, and that 1.05 points per possession was the 5th highest mark on their defense all season long, you begin to think maybe that wasn't all that bad. In other words given our highly ranked offense and their highly ranked defense, we scored about what was expected.
It's the fact they scored 81 when they were predicted to score 59 which was quite alarming.
I think that's how these things need evaluated anyways. Given a teams rating and their opponent rating (off vs def) what were they expected to do and what actually happened. Given that even filtering the results from February onward our offense was still at 6th in adjusted off efficiency, I'm guessing we didn't drop off all that much.