The idea for this is based on a game I played blindside in (many years ago). I spent all the first half not being able to put a finger on the SH. When I discussed my problem with our coach he turned and counted the number in our opponents team. He got up to 16. Investigation revealed that they had two SHs, but no-one could tell because we were not rich enought to afford shirts with numbers on.
This got me pondering on something that has irritated me for a while, namely, how often ruck ball is slowed waiting for the SH to sprint half way across the pitch. So why wait for them? Why not coach any player who is first to arrive at the base of a ruck to assess whether moving the ball quckly is on? While this might disrupt some practiced attacking patterns you would be attacking a disrupted defence.