But this wasn't a street fight. Look at the vid again, the police was grabbing the 1st woman's arm, she was trying to get free (resisting arrest looks like it), the 2nd one tried to help her to get free, and she did push the police man, but it was no fight...
The 2 woman were upset, and their goal was to get free, not inflict harm on the police. Not to run. They just wanted to argue, *****, scream.
I'm no police, but that's how I see it. The guy, after getting pushed, should have said clearly that they're both under arrest, and put their hands on the car (which he might have done previously, not shown by video...)
Then, if no reaction, he could have grabbed one, put her on the car, and cuff her. Simply by grabbing one of her arms from the wrist, but in her arm in her back, and put her on the hood car... Physically, with strength... Cuff her. If the other attacks him during that time, or something then he has a problem.
Which raises the point, why was he alone? Did he call for backup? If he didn't, he definitely should have, and could have simply waited for his backup to arrive so that another officer to handle the 2nd woman if he was not able to do so by himself, without actually having to resort to physical violence and punching them...
Calling backup is especially important if he think he'll have problems doing the arrests by himself. The situation could have been handled much better imho.