Watching England play rugby union Chris Aston missed a tackle the commentators said rugby league players have good technique so why do two men need to commit to the tackle

Because the attackers are gonna be better at breaking through. And its more about holding them to the ground as well.

The technique now isn't so much as to ground the ball carrier but to tie him up to i) stop him from slipping a pass away in the tackle and ii) to slow the play down so the defence can be set.