As I understand it, there are 93 U.S. Attorneys. They serve at the pleasure of the President. It is normal for them to all offer their resignations when a new President takes office. And it is normal for many of them to be replaced on such an occasion.
If I recall correctly, Bill Clinton replaced all of the U.S. Attorneys when he took office. That was not normal. But what it did do was stop all investigations into Clinton activities and politicize the entire U.S. Attorney system.
Democrats and their media lapdogs are, as usual, screaming about things they do and not what is happening. It’s called projection.
Clinton’s total tally was 118, he kept firing them when they dug up dirt on his activities.