Also weight only means so much if your technique and playing style fail to exploit it. Ireland are good at having their forwards running onto the ball and they aim between defenders, not at them. We on the other hand take the ball static, get hit by a defender who is moving faster than the ball carrier and aim for the most dense clump of defenders we can find. Our forwards carrying is pretty much a check list of all the things that are poor technique. If anything it's a wonder we make ground going forward at all. Despite their reputation, the Irish don't try to run over players, they look for whatever gaps are there and run at those. Much easier to make ground when someone can only get their arm in your way rather than their entire body.