Forgive my ignorance for this game, but it looks like Lomu was a very strong guy, those guys in white (I am assuming they must be Britons) seem to have a hard time bringing him down.
Now if you got like 4 or 5 sumo wrestlers kind of guys, one holds the ball, the others protect him and they start walking towards the other end to score a try, I am sure tackling them would be next to impossible - would that like work.