A team of a nurse or social worker + cop is the alternative to (generally) 2 cops. Whatever the funding mechanism behind the doors, you're switching out a cop for an alternative person, which is exactly what the defund movement has always been asking for. See some quotes below:

https://defundthepolice.org/alternatives-to-police-services/

The police service is a dangerous option for people experiencing a mental health crisis—but for many, it’s the only option. By defunding the police, significant resources can be reallocated to create a new community emergency services to support the mental health needs of our vulnerable community members. Teams trained in de-escalation and who root their work in community-informed practices could provide crisis support and care.

...

One common refrain in opposition to defunding the police assumes that our society will not be able to effectively respond to violent crime. But we have to remember that police do not prevent violence. In most incidents of violent crime, police are responding to a crime that has already taken place. When this happens, what we need from police is a service that will investigate the crime, and perhaps prevent such crimes from occurring in future.

Policing is ill-equipped to suit these needs. When victims are not the right kinds of victims, police have utterly failed, and at times refused to take the threat seriously. Why would we rely on an institution that has consistently proven that it is rife with systemic anti-Blackness and other forms of discrimination that result in certain communities being deemed unworthy of support? Instead of relying on police, we could rely on investigators from other sectors to carry out investigations. Social workers, sociologists, forensic scientists, doctors, researchers, and other well-trained individuals to fulfill our needs when violent crimes take place.

...

If we were to defund the police, we could create new investigative services where diverse teams of researchers and investigators, with a mix of scientific, public health and sociological expertise are able to attend to our investigative needs without the inherent anti-Blackness with which the police services approach our unsolved cases. Additionally, we could put money into programs attending to the food security and housing security needs of people living in precarity, to reduce the likelihood that desperate people unable to have their basic needs met would resort to the extraordinary step of attempting to meet their needs through theft.

In Europe, its not uncommon for nurses and paramedics to volunteer on weekend nights around cities, primarily to supplement the underfunded and understaffed ambulance service by patrolling with a first aid kit and defibrillator since it gets easy credits towards their degrees. While there is a working relationship with Police, its pretty established in those roles that keeping the cops at a bit of a distance tends to be for the better. If you have the cops about, people tend to lie more and get worse care because of it. They also tend to consent less. I'm not saying incidents don't happen, but having cops about causes more of then than it prevents.

someone trained in protecting

I don't know that I've ever seen a cop protecting anything other than a storefront

Okay so send them with another nurse or some security.

Security officers are wayyy different from cops.