This is an area where I think the FAA should get involved. Development of a drone specific instruction program aside, I believe anyone teaching a flight course should have, at minimum, passed the FAA fundamentals of instruction course. That is the cornerstone for which all other flight instruction courses are built on.
As for who teaches law enforcement, a little light research will show they tend to work totally within the established law enforcement and military communities. They maintain much better control of their information, use a common structure, and end up with less confusion. Companies that desire to enter such a training field would do well by hiring people with a long previous history in law enforcement and LEA training and use them and their credentials to build and market their products.