That is simply not true. An employer must only show that the assigned salary for the applicant corresponds to salaries paid to US citizens. But the salary itself is always set by the employer.
The amount is too low for Americans to be able to accept the positions. Also, the H1B visa program is putting Americans out of work.
It is not hard to show that the assigned salary corresponds if you have put most of the people out of work and so driven down wages by foreign H1B recipients foreign workers.
The salary itself IS set by the employer using the guidelines established in the program. The guidelines on salaries are too low, that is the point.
I feel like you are parsing in an attempt to avoid the issue. Am I incorrect in that?