"since women started being cops, police had to change their procedure to require at least 2 police officers if available for routine traffic stops. this was due to a female cop being beaten up during a trafic stop cause the driver had warrants. "
Male cops get beaten up too. Also shot. You're never too big to get taken down by a bullet.
Police work these days has become a much more complex job, with various specialities. When investigating domestic disputes, for example, the single most important thing is to prevent violence from starting, not to be able to win a fight if it does start (though if one does, the police generally have batons, pepper spray, tazers, and guns on them, while the people they're confronting, if they have any weapons, would need to go away to get them, so that's quite a bit of an advantage to the cops, male or female, to begin with).
There are other situations like crowd control, where size is an advantage (though a bigger one is the dozen other cops standing next to you). Then there are K-9 units, and there are SWAT teams, and there are detectives. And community liasons, commercial/corporate crime, computer crime, and so on. There is no one skill that's best for all these requirements, and no one person best at all these fields either.
You probably also don't realize how much paper work police these days are drowned in.
Policing has gone a long way since it was thugs with sticks hired by the King to keep the rabble inside at night.