Just to nitpick it is more important to be the corresponding author. While there is often a fight over who gets to be the primary author (i.e. the junior person

Just to nitpick it is more important to be the corresponding author. While there is often a fight over who gets to be the primary author (i.e. the junior person who did all the work), it is nothing compared to the fights that go on between the PIs as to who will be the corresponding author. Grants and millions of dollars are at stake in these fights.