They could have done the replacement of these Clinton supporters with cronies by other means - but the means they chose was to create false charges and go completely out of their way to humiliate these people on the way out (taking the seats out of the van and wetting it down inside- really?).
She had a choice. Fire them and give the position to their friends but that looked bad. So instead sh accuses them of embezzlement to provide herself political cover.
Despicable.