It does rather feel like Claudius might be concerned Hamlet and Laertes might start fighting in an unorganized way if he doesn’t intervene. And he definitely doesn’t want a fist fight because a fist fight will make it a lot harder for Laertes to “accidentally” kill Hamlet with a poisoned sword.
It feels a bit like Claudius is trying to defuse this back and forth so they can get to the business of killing Hamlet.
The Hamlet Project 