I can't remember which year it was, but the first origin game about 4 to 5 years ago when the ref kept the players back only 7 to 8 metres or something and only 1 try was scored. The game was the most boring origin game ever because it was just one out hitups and the attack didn't have enough time or space to be able to pull out anything creative.
That could equally be explained by the players suddenly being faced with a situation where they had to actually be creative to get up field (instead of being given 10m and momentum) and having no answers.
The modern wrestling/mauling in the tackle in RL today is more like RU than anything that we saw under the 5m rule.
The reason the mauling/wrestling exists is because 10m is physically too much for RL to be officiated with a fast "held" rule and play-the-ball. This is all compounded by the obvious bias that is given in favour of attackers over defenders at the ruck.
Frank Hyde suggested that we can keep the 10m space, but make sure the attack and defence are both back 5m from the ruck. If we go to 2 referees, this could actually work quite well as both referees would enforce the 5m distances, and still be close enough to see what is going on at the ruck.
In my view we should keep 10m rule, but be calling "held" far quicker - But that can only happen if some off-sets are given to the defence - otherwise referees will just keep penalising defenders for not releasing, not marking, and/or not getting back 10m.
I would keep the 10m rule, but relieve the pressure on the defence. If teams want a lightening fast play-the-ball, let them have it - but stop rewarding the attack if they choose to run at defenders who haven't had a reasonable time to get square at marker, or get back to 10m.
If the attack wants square markers and the full 10m then they can have it...by waiting just a few seconds longer. BUT if the attackers choose to go early, then stop rewarding them for trying to get cheap penalties from retreating defenders instead of playing football. All of that would force attack to spread the ball a little wider, just to clear the ruck.
The 10m rule worked really well in 1994-1996 - until everyone worked out that there was cheap 10m on offer if you just ploughed ahead from dummy-half or a hit-up.