Many company QA systems check, and confirm by examination, that the new mechanics and engineers know how to use the company's systems and are familiar with how the company wants the new guys to do their work, and that the company is getting what it pays for.
This is because all are working on the company's approval - not on their own Licences. And the company has to show "Competency" as well as qualification (your licence)
I'll descibe my company's system
When the guy/girl has shown that they understand what is required of them and how they should conduct themselves, they get approved to work and a company Stamp/Number. This is also checked every two years for approval renewals through a small simplified exam.
All exams are "open book" and not time-bound. The pass mark is very high as the applicant is encouraged to go and find the answer if they don't know it.
Yes, this desk-bound QA type also has approvals and does Technical (competency) assessments of all engineers to allow approvals. And sometimes QA reject engineers approval applications due to a (quantified) lack of knowledge for the levels requested.
While there is no "Licence" required for QA, (in manufacturing, design or maintenance) is is generally accepted practice to employ QA personnel with relevant experience in the field in which they will audit. This means that some of the QA staff in your areas aren't necesasrily "Licenced" nor do they need to be - but they may be extremely experienced in their field and may share some duties which do not need to be reserved for any particular "trade". In airlines, this experience may range from assessing Hostie's duties to ticketing and baggage handling.
The CAA expect QA staff to be QA qualified and competent too - so QA staff go on QA courses as well as courses for their specialist knowledge.
Don't forget, Walt, that many "QA types" are Poachers-cum-Gamekeepers. We know most of the mistakes and many of the 'tricks' too. And we are likely to have made/done them before you did.