It comes as something of a surprise that rugby is concerned about any injuries, least of all head injuries.
Still, the world changes in strange ways. My son had his first mixed martial arts fight under professional rules a couple of weeks ago. The following bout, on the same professional rules which allow pretty much anything except elbows and head butts, had a couple of sheilas who went at it real hard, with one of them losing a fair bit of claret from early in the first round and a lot more claret in the second round and then getting decked hard, but not quite for the count, in the closing seconds of the second round. As the third round was about to start it was announced that the sheilas wouldn’t be be fighting any more “because we don’t want people to get hurt”. It seems I misunderstood something about the nature of the event.