That's true... as we know, if you change one thing on a severe wx day, it can knock it back from historic to something less than that. That's why the high end days are uncommon and the super high end days are even more rare.
Something to consider about Morch. It was about a 10 day period of extreme warmth bookended with lesser positive departures. If that period had fallen from, say, March 27 to April 5, would it have been quite the same? The March departures wouldn't have been as ridiculous. Unlike a tornado outbreak, we are slaves to the calendar when it comes to extreme monthly temp anomalies.