Well it's not just a "belief" actually, but the words of many chief officers around the country, including a few at trainings I attended at my own city's police headquarters.
There are also dozens of articles like this one with a simple google search:
Training has actually very little to do with how officers respond. It is completely reasonable for officers to be able to defend themselves if they are threatened physically, and to use lethal force if their life is in danger.
As many know though, police brutality has little to do with this, and the officers that are in the wrong aren't following training.
Do you really think officers are trained to beat the shit out of people? Give me a break.
The problem is who these departments are hiring. And in this instance my "weak, gender-based argument" is perfectly valid. The perfect candidate for a Phoenix Police Officer is someone who can barely pass a written test but then can make up for it in sheer brute strength.
Women are different than men. They aren't built the same way, and they aren't driven the same way. It is statistically improbable to find a woman who would go into a school and shoot a bunch of people, or rape little boys and then kill and bury them to later be known as a serial killer. Women are typically not the ones involved in bar brawls, they aren't cartel leaders, they aren't responsible for the majority of gang violence, and they aren't the stars of these videos beating the shit out of people. It's statistics dude, it's not a weak argument.
Female officers are typically tiny, cross-fit types in order to pass these physical exams. So pray do tell me, why aren't women the ones, in fear of their lives, who are mowing down unarmed civilians all the time?
Why is it big, burly men doing that?
Could it be that women have a different mindset and approach to situations making them more suitable to handling said situations?
Just as the article states, women have a different approach to policing, which is anti-authoritarian in nature, and that is important.