If you're in auditing line and asking you not join another auditing firm is like not letting a doctor practise for two years after quiting from one of the hospitals. Every other hospital is a competition.

Typical company policy here, want to grab you by the balls even after you resign. Honestly, do you have any other options other than auditing companies?

I doubt they will go after you even after they find out. A waste of legal fees for them.