I think you're right. The prosecutors needed a sworn Complaint to make an arrest and hold the defendants, but I think the one count in this Complaint is just a placeholder-- the prosecution will probably be back with a much longer set of charges once they put the case before a grand jury.
The federal process needs a charge filed within 48 hours to continue holding somebody in custody.
Whatever. Hillary's lawn jockeys in the Federal "justice" system will have their little show trial, like the Russians did under Stalin:
our federal overlords will demand that the peasants be made and example of in order to stop any future uppityness.