The problem with tackling lower is that it enables the attacking players to off load more often for second phase movements. Additionally, there is much more chance of the defending tackler to injure himself by tackling low and hitting his head on the thigh, hip, leg of the attacking player so could end up with lots of HIA's/concussions so good tackling techniques have got to be put into place at training.
This is the time for Hook and Co to use their coaching skills, if they actually have any, to get our guys to tackle very effectively without causing any shoulder charges, head highs and head collisions in tackles to avoid sin bins/send offs and injuries to our players.