That is correct. I can personally attest to that for where I live. The local cops have free use of my shooting club and they hold their qualifications there. It is pretty amusing watching them qualify. (I saw that once last summer.) I wouldn't call them bumbling idiots, but they definitely are not shooting professionals.
My advice to all traveling there. If a Thai police officer yells "STOP" you better be skidding to a stop. They were really good. At least those training that day were.
None were in uniform so maybe they were an elite group, not regular street cops.