Actually, the NREMT tests to the standards of the DOT EMT curriculum, which may be quantified as the candidate meeting the minimum standards for measured competency.
Each state is actually in its own little world, allowing or disallowing skills or medications for different levels of practice. That's why there should be one national standard for each level of EMS certification.
An EMT class that teaches "this is what they tell you in the book, but this is how we do it in real life" is doing a disservice to the students. Teach the DOT standard curriculum and any add-ons should be taught as a secondary module.