Early proto-MMA events in the US & Brazil literally had no rules (Google 'vale tudo'), and included groin strikes & eye gouges (Google 'Keith Hackney Joe Son'). They were actually underground fighting events, some held in illegal clubs, warehouses, basements- and, they were won by BJJ & Muay Thai guys- the constituent martial arts that make up what we call MMA today. You can actually find Vale Tudo fights on Youtube to see for yourself! Early UFC events also literally had no rules as well- and they were won by, first BJJ and then wrestling. TMA guys didn't fare so well even in the complete absence of rules.
Police & military units the world over study MMA or the individual martial arts that make up MMA (BJJ, wrestling, boxing etc.)- not Kung Fu. Jocko Willink, a highly decorated 20 year Navy SEAL commander, is also a BJJ blackbelt and has specifically said that he used jiu-jitsu to subdue militants in close quarter combat, and that TMAs don't work. On the Joe Rogan podcast he talked about fighting other SEALs in the 90s who were into TMAs and beating them with jiu-jitsu..... Wouldn't an actual Navy SEAL with combat experience know more about what works in a 'real life situation'?
I don't understand how 'person to separate the two fighters' makes it less realistic- they're there to prevent someone who's been KOed from suffering any more unnecessary strikes