Quote Dico="Dico"Your players should learn the rules then.'"
If you wanted to be pedantic you could give a penalty on virtually every play.
A defender in the line moving a fraction before the ball has cleared the ruck, a tackler holding on a second too long after 'held' has been called, the markers being almost but not quite square, the player in possession not playing the ball 100% in accordance with the rules.
It happens. It has always happened. It always will happen.
Good referees use their judgement to decide when they need to act. Bad referees think that the game revolves around them and take even the slightest infringement as a personal affront.