I would support Brian McCann being able to select the pitcher of his choice to throw a fastball at Betances' head. I guarantee you Betances' head hunting days would be over for good after that experience.
Honestly, I can't think of anything more cowardly than throwing a baseball at someone. As archaic as fighting is in hockey, I can at least respect the fact that it's two men on equal terms. In baseball it's like giving one man a gun and the other a stick.
MLB also needs to levy heavy fines on anyone who leaves the bench. The first fight was basically over until the bullpen pitchers came sprinting in from the OF to stir things up again.
And much like umpires catchers need to go back to being seen and not heard. A catcher should never be the one instigating a fight. There's no reason a catcher needs to talk back if the batter's complaining about the strike zone. Let the umpire do his job and keep your mouth shut.