Good question Alistair
My understanding is that the current elite and panel guidance is "less is more" - so not a running commentsry. At all levels referee calls should be proactive & preventative not reactive after the event. The player skill levels (and propensity to cheat) will usually determine just how much you need to manage them !
At the higher professional Levels the skill and knowledge of the players should be high enough for them to know when a ruck has formed, and so when hands are not allowed. In the tackle situation the referee has a clear view and can call when the criteria are met, whilst the players themselves are in a contact contest situation and things happen very fast so Wayne calling tackle sets the gates, determines tackler must release & roll, tackled player to do something positive (place, pass, release) and defines only players on their feet can contest in the jackle, and
At the lower community rugby levels, as you have no doubt discovered, the referee may need to be clear about tackle, ruck transition, or maul, and keeping players through the gate or behind the back fo