It has alot to do with age. And the fact the players are all in sync with a plan. No rouge pay check players in the way we have. It helps that they are smashing all competition so far and riding on a german cock.
Whether or not they get injured has NOTHING to do with that.....
You're just running further and further away from the simple fact that the majority of injuries are simply bad luck.... Particularly broken/fractured bones and other impact injuries.