Summarized as bullet points? or as a paragraph?
I am not sure if the job posting of similar responsibilities will help you in proving that you worked in the mentioned NOC, but there is no harm in including LOE with those job posting and stating your view. I think it should strengthen your case.
They might be looking for those job responsibilities that should be present (as expected of NOC) but are missing.
There could be another reason, which we completely missed, there could be chance that the officers are in a doubt that you have same responsibilities of some other NOC's responsibilities (such as, Computer programmer and Software engineer, they both have different NOC, but there are some similarities in the both NOC's job responsibilities). They just want to make sure you have correct NOC stated in your application.
Seniors?