Couple of helpful info for you/other folks:

- The Department of Labor (DOL) does not allow PERM applicants to use experience gained at the PERM petitioning employer ( in your case its company "A")
- First, I would like to let you know that the minimum requirements for the PERM application are not based on your background.  The PERM requirements - degree, years of experience and special skills - are determined by your manager based on what job requires.  Thus, the company needs to  assess if you possessed all of the PERM requirements before you joined the PERM petitioning employer. If you did not possess required degree, years of experience and special skills before joining PERM petitioning employer, they cannot file a PERM application for you.
- FYI: Generally , its  (BS + 2-4 / MS + 1-2).

NOTE: These are concrete info that I have from my lawyer. I'd highly recommend you to consult w/ your lawyer based on the above inputs.

~GoodLuck