Quote Richie="Richie"Number of players isn't the main factor here. It's what happens to put the ball back in play.
Have a pile on and a supposed contest for possession and you have RU.
Have everyone get out of the way and the player in possession put the ball back in play and you have RL.
Have everyone get out of the way, give the ball to the ref and he put it down to bring into play (and some other rules about obstruction) and you have american football.
You could change the numbers on the pitch, but unless the method of recycling possession is altered, it's still fundamentally the same game.'"
I don't know if I agree with you here.
The "pile up" that you mention are certainly competitive (although there are some bizarre rules surrounding them !) but, if these were limited to 6 phases, their game would change beyond all recognition.
Although I don't expect that they will drop to 13 players, IF they did, the drive towards a merger of the 2 sports would come from all sides.
The big boys in league would see £££ signs and the union brigade mat see to chance to rid the world of RL.