When a great scrummaging side pulverizes their rivals, there is no mercy rule.
It's up to the pack on roller skates to deal with the drama by improving or using their subs bench otherwise any competent referee is going to penalize them and probably send someone to the sinbin.
Then the problem will get worse. That's the skill and reward for a side with outstanding scrum technique.
So why does World Rugby have a rule which says if two specialist props are injured during a match, scrums will revert to golden oldie rules as we saw when the Springboks hosted the All Blacks at Ellis Park.
Springbok captain Schalk Burger missed a trick when his side had the All Blacks on the rack.