Don't forget there will be a number of the pilots on 457 visas because their partner got the 457 visa.
If a doctor has a family including a husband pilot, her whole family get the 457 visa. He has no work restrictions, but she the doctor has work restrictions and employment requirements to meet while she is on that visa.
* Also once here in Australia he could claim "Domestic Violence" against his wife and then be issued with a permanent visa. They could then reconcile a while later and sponsor her for a Partner Visa. :- a good chance this tactic will be used with the new changes.