Not really.

The only reason there is one fewer name than expected is because of Bush, which had the father appear on the ballot four times and the son appear twice. The Bush family was a very old school political dynastic family.

The only outlier on the Democratic side is Hillary Clinton in 2016. She used her husband’s political career to help her, but they were a self made political family. You also have the case where Biden could have been on the 2016 ballot and there would be no change in the number of names.