In a statement ARLC interim chief executive Shane Mattiske thanked Harrigan and Raper for their work.
"Bill has made an incredible contribution to refereeing in a career that will forever stand out in the game's record books,'' Mattiske said.
"He and Stuart have worked incredibly hard over the last two years in particular and there is a strong sense of gratitude on our part for their efforts, but we also believe that a new structure is needed.''
McGuirk said the restructured leadership team would be a step forward for the game.
"Bill and Stuart have been part of a dual coaching structure and it is time to move to a new model.
"Nobody could criticise their commitment but as we have reviewed the year from a number of perspectives it has become clear that we need one person to manage what is a high performance team.
"Bill and Stuart have increased the depth of talent in the squad and that has been one of the real positives over the last two years.''