Mueller is finding everything but Russian collusion.
Mueller is just trying to cover his a$$.
Mueller is literally trying to charge anyone within arms reach of Trump with everything that resembles what Hillary is guilty of doing, selling her office, failing to establish as a foreign agent, etc.
This is called going on the offense and is a tactic to make the eventual investigation of Hillary seem retalliatory... also, if they give weak sentences, they can give weak sentences to Hillary as well.