Eddie,
You are very probably correct, but some AWIs are not aware, in one recent case a LAME was taken to task because the particular AWI did not accept the fact that the existing detailed workshop approval included AC 43.13A/B --- all too typical of 50 AWIs equals 50 or more interpretation of the "rules".
At one stage (2006/7??) we had an instrument that declared the whole FAA AC library was approve data, to eliminate the "approval industry". Byron was the DAS at the time. The instrument Issue 1 came from Greg Vaughan.
It was reissued once by Mark Sinclair, but when the "new" crew (you in CASA know who I am referring to) took over, not only did they not re-issue the same Instrument again (most have a time limit imposed by the Legislative Instruments Act 2003) but the replacement Issue 3 completely reversed the intent, and specifically requiring CASA approval (at great expense) for each and every FAA AC for each and every individual workshop.
Ergo, "approval industry" back in full swing, with all the associated costs and delays.
Tootle pip!!