Agreed on the cheap and many possibilities of robots.
Swarms of cheap ones are far more effective than a large expensive one.
They just have to get there too… literally close the range with a would be assailant.
And tackling is a great idea. But… when you talk about taking people down you run into a bunch of evolutionary adaptions that people have to prevent it. Its the same way creatures eat each other.
Also… if you’re tackling they have to be fast.
The good part about tackling things is… its a very effective strategy. Everything from white blood cells to ants to cheetahs tackle stuff.
And less-lethal drone warden (the macho version of Teddy Bear Handler) does sound like the coolest job on the police force 
