You are correct to point out the problem , the law and the guidance are not really in syncInteresting. So if a defender comes around and stands next to attacking SH and ref calls 'use it'? Would we tell the defender to leave SH alone until he passes it?
We have a group of blue players formed up expecting a maul, with the ball at the back
It's not a maul, so they can't move forward
But if they do move forward we are told not give a PK for obstruction (as per the law) but instead a scrum
But if it's not a maul there is no Law that allows the referee to order them to 'use it' but we are told to tell them that anyway
And if it's not a maul then the ball has left the line of touch so the lineout is over , so we can't penalise blue for leaving the lineout ... But we are told that if blue retreat then to PK them for it
And if it's not a maul, as you say, blue can come round to the red side of the ball
Let's face it, it's a mess