You’re probably right that it’s the rules that need looking at - I’m not defending Stephen’s tackle, just saying that IMO Cunningham’s was worse. If your intention is to deliberately body check a player running at speed when the ball is nowhere near you, then you deserve a red.
Maybe, but the other big difference in those challenges was that Cunningham’s foul was deliberate with no attempt whatsoever to play the ball - whereas Stephens made what seemed to be a genuine attempt to play the ball. Shame that refs don’t seem to take that into account.