They should all have waited until next spring. All primaries should be on the same day, which would spare us and the candidates the marathon campaign stops, not to mention millions of campaign dollars. And all debates should be on the radio.
Ah well, back to the real world...
I think there is some benefit to having a staggered sequence of primaries, but it might be better to have the order of the states' primaries determined by lottery, some reasonably-short time beforehand. For example, on December 1, there could be a drawing to see which five states should hold a primary on the first Tuesday after January 2. On December 15, there would be a drawing for five states two weeks after that. On December 30, another five states the Tuesday after that, etc. There would thus be slightly over 30 days' notice for primary. Enough time to manage the logistics, but not so much time as to encourage overly-long targeted campaigns.