It certainly is. The amount of energy in impacts is colossal and transmitted throughout the entire body resulting in players picking up career ending injuries and worse. This is why there are continual calls to have the schedules slimmed down at club and international level or have a few professional clubs with much larger squads backed by the RFU. The recent changes to carding rules for dangerous tackles and contact to the head are excellent. The message as in ice hockey is getting through that such actions will be severely penalized. However for those players in the earlier ages of the professional sport the indications are worrying hence the class lawsuit being pursued.