Tom:
Here in NJ the AHJ's are Lic by the State, and we can either work for a third party agency, or for a municipality, or the State
We have to take the tests, pass them, and go to CE seminars (min of 3 days) to renew our Lic. If we are an 'administrator (Sub-Code), that requires additional 2 days of CE.
NJ recently started Lic of Home Inspectors (about time). I do not know all of the specifics, so I won't comment at this time.
Yes, we do have some 'multi-hat' guys, I know one who is Elec, Fire, Plumb and Building, and I guess he's good at it.
BTW, EC's here need 34 hours of CE every reneval also (3 year cycle)
The above is for informational purposes only, not intended to start a firestorm, or ruffle anyone's feathers
John