That's a good shout. He used to scream at defenders until they were organised exactly as he wished, blamed them for every goal and generally bullied them into being ruthlessly risk-aversive and fully alert at all times.
Clemence, Souness or Dalglish would not only improve the side but also lead it. And Terry McDermott would link the midfield and forwards into attacking moves that are currently only hinted at. But probably the player who'd improve the side but also be the player of Klopp's dreams would be a young Emlyn Hughes, probably the most Klopp-like character there's ever been.