Dear Fedrikhof,
You have given direction for a very valid method to decide, "whether the training provider really knows, what he claims to be able to do?"
However, I think, there is an exception. The question, "How many times has the class been taught in its present form?" does not fit if the training content has been configured for the target recipient. At least I feel, that it never holds that a given content is good only if it has been used 'n' number of times.
I believe and have witnessed, that a trainer who knows his business can make it happen right the first time also.
Regards.