The second officer definitely took control of this cluster.
I spent my public service career in a suburban/urban area where back-up was usually close. I don't know where this took place and don't want to judge, but I will remark that many of the horrifying video footage we watch occurs when someone does in alone when he or she should have waited for assistance. While not always effective and better deployed when back-up is on scene, but pepper spray or taser deployment may well have been better alternatives to debating with the suspect and ineffective hand techniques.
As for the off duty incident, I think extracting the victim (who shouldn't have confronted a gang to begin with) and calling the working police would have been a wiser strategy than taking cell phone photos like every other assault victim you've ever encountered. I also wonder if the off duty officer had a gun on him.