Everyone thinks they are an expert in dog training

I just do not get it. Why does everyone think they are an expert when it comes to dog training. The groomer runs puppy classes, so does the shop assistant at the pet shop or the vet nurse.
Would you send your kids to school with the hair dresser, the nurse or the shop assistant. I do not think so.
I would not even dream of clipping a dog for a client, say I can work the cash register or walk into a vet clinic and apply for a job as a nurse.
It is a different skill set. There is actually a formal education for dog trainers (Cert IV in Companion Animal Services in Australia), there are accrediting bodies for trainers such as the Delta Institute or the Pet Professional Guild. Just to mention the one that are the choice of the positive reinforcement trainers.
If you contact a dog trainer ask for their education, experience and accreditation. And sit in in one of their classes to make sure you like what you see.
If it feels wrong it probably is wrong!